Protective rubber track shoes for excavator

Abstract

Provided herein is a protective rubber track shoe for an excavator, which includes a first-stage rubber mix and a second-stage rubber mix. The first-stage rubber mix consists of a natural rubber, a chloroprene rubber, a butadiene rubber, a styrene-butadiene rubber, a tire reclaim rubber, a 120-mesh rubber powder, zinc oxide, stearic acid, an anti-aging agent 3100, an anti-aging agent CTU, paraffin wax, an intermediate super abrasion furnace carbon black and an aromatic oil. The second-stage rubber mix consists of the first-stage rubber mix, sulfur, an accelerator CZ and an auxiliary agent.

Claims

1. A protective rubber track shoe for an excavator, comprising: a first-stage rubber mix; and a second-stage rubber mix; wherein the first-stage rubber mix consists of 22-25 parts by weight of a natural rubber, 4-5 parts by weight of a chloroprene rubber, 40-42 parts by weight of a butadiene rubber, 30-32 parts by weight of a styrene-butadiene rubber, 60 parts by weight of a tire reclaim rubber, 8 parts by weight of a 120-mesh rubber powder, 4.0-6.0 parts by weight of zinc oxide, 2.0-3.0 parts by weight of stearic acid, 1.9-2.3 parts by weight of an anti-aging agent 0.8 part by weight of paraffin wax, 55-59 parts by weight of an intermediate super abrasion furnace carbon black and 5.8-6.2 parts by weight of an aromatic oil; and the second-stage rubber mix consists of 233.5-249.3 parts by weight of the first-stage rubber mix, 1.0-1.2 parts by weight of sulfur, 1.3-1.5 parts by weight of an accelerator and 3.8-4.2 parts by weight of an auxiliary agent.

Description

DETAILED DESCRIPTION OF EXAMPLES

(1) The present disclosure will be further described below with reference to the embodiments.

Example 1

(2) Provided herein was a protective rubber track shoe for an excavator, including a first-stage rubber mix and a second rubber mix.

(3) The first-stage rubber mix consisted of 24 parts by weight of a natural rubber SCRS, 4 parts by weight of a W-type chloroprene rubber, 41 parts by weight of a butadiene rubber, 31 parts by weight of a styrene-butadiene rubber, 60 parts by weight of a tire reclaim rubber, 8 parts by weight of a 120-mesh rubber powder, 5 parts by weight of zinc oxide, 2.5 parts by weight of stearic acid, 1.0 part by weight of an anti-aging agent 3100, 1.1 parts by weight of an anti-aging agent CTU, 0.8 part by weight of paraffin wax, 57 parts by weight of an intermediate super abrasion furnace carbon black and 6 parts by weight of an aromatic oil.

(4) The second-stage rubber mix consisted of 241.4 parts by weight of the first-stage rubber mix, 1.1 parts by weight of sulfur, 1.4 parts by weight of an accelerator CZ and 4.0 parts by weight of an auxiliary agent.

Example 2

(5) Provided herein was a comparative sample, in which the chloroprene rubber was absent.

(6) The comparative sample included a first-stage rubber mix and a second rubber mix. The first-stage rubber mix consisted of 28 parts by weight of a natural rubber SCRS, 41 parts by weight of a butadiene rubber, 31 parts by weight of a styrene-butadiene rubber, 60 parts by weight of a tire reclaim rubber, 8 parts by weight of a 120-mesh rubber powder, 5 parts by weight of zinc oxide, 2.5 parts by weight of stearic acid, 1.0 part by weight of a new anti-aging agent 3100, 1.1 parts by weight of a no pollution anti-aging agent CTU, 0.8 parts by weight of paraffin wax, 57 parts by weight of an intermediate super abrasion furnace carbon black and 6 parts by weight of an aromatic oil.

(7) The second-stage rubber mix consisted of 241.4 parts by weight of the first-stage rubber mix, 1.1 parts by weight of sulfur, 1.4 parts by weight of an accelerator CZ and 4.0 parts by weight of an auxiliary agent.

Example 3

(8) Provided herein was a comparative sample, in which the rubber powder was absent.

(9) The first-stage rubber mix consisted of 24 parts by weight of a natural rubber SCRS, 4 parts by weight of a W-type chloroprene rubber, 41 parts by weight of a butadiene rubber, 31 parts by weight of a styrene-butadiene rubber, 60 parts by weight of a tire reclaim rubber, 5 parts by weight of zinc oxide, 2.5 parts by weight of stearic acid, 1.0 part by weight of a new anti-aging agent 3100, 1.1 parts by weight of a no pollution anti-aging agent CTU, 0.8 parts by weight of paraffin wax, 57 parts by weight of an intermediate super abrasion furnace carbon black and 6 parts by weight of an aromatic oil.

(10) The second-stage rubber mix consisted of 233.4 parts by weight of the first-stage rubber mix, 1.1 parts by weight of sulfur, 1.4 parts by weight of an accelerator CZ and 4.0 parts by weight of an auxiliary agent.

Example 4

(11) Provided herein was a comparative sample, in which a combination of a common anti-aging agent 4010NA and an anti-aging agent D was used.

(12) The first-stage rubber mix consisted of 24 parts by weight of a natural rubber SCRS, 4 parts by weight of a W-type chloroprene rubber, 41 parts by weight of a butadiene rubber, 31 parts by weight of a styrene-butadiene rubber, 60 parts by weight of a tire reclaim rubber, 8 parts by weight of a 120-mesh rubber powder, 5 parts by weight of zinc oxide, 2.5 parts by weight of stearic acid, 1.0 part by weight of a common anti-aging agent 4010NA, 1.1 parts by weight of a anti-aging agent D, 0.8 parts by weight of paraffin wax, 57 parts by weight of an intermediate super abrasion furnace carbon black and 6 parts by weight of an aromatic oil.

(13) The second-stage rubber mix consisted of 241.4 parts by weight of the first-stage rubber mix, 1.1 parts by weight of sulfur, 1.4 parts by weight of an accelerator CZ and 4.0 parts by weight of an auxiliary agent.

Example 5

(14) The formula used herein was a comparative formula, in which a common anti-aging agent 4010NA and an anti-aging agent 4020 were added.

(15) The first-stage rubber mix consisted of 24 parts by weight of a natural rubber SCRS, 4 parts by weight of a W-type chloroprene rubber, 41 parts by weight of a butadiene rubber, 31 parts by weight of a styrene-butadiene rubber, 60 parts by weight of a tire reclaim rubber, 8 parts by weight of a 120-mesh rubber powder, 5 parts by weight of zinc oxide, 2.5 parts by weight of stearic acid, 1.0 part by weight of a common anti-aging agent 4010NA, 1.1 parts by weight of an anti-aging agent 4020, 0.8 parts by weight of paraffin wax, 57 parts by weight of an intermediate super abrasion furnace carbon black and 6 parts by weight of an aromatic oil.

(16) The second-stage rubber mix consisted of 241.4 parts by weight of the first-stage rubber mix, 1.1 parts by weight of sulfur, 1.4 parts by weight of an accelerator CZ and 4.0 parts by weight of an auxiliary agent.

(17) Performance Test

(18) 1. Physical and Mechanical Properties

(19) TABLE-US-00001 TABLE 1 Comparison of physical and mechanical properties of the protective rubber track shoes prepared in Examples 1-5 Properties Items Example 1 Example 2 Example 3 Example 4 Example 5 Mechanical Tensile strength (MPa) 18.52 16.73 18.71 17.86 18.68 property Stress at an elongation 3.62 2.56 3.89 3.21 3.42 100% (MPa) Stress at an elongation 10.91 8.26 10.27 9.89 9.56 300% (MPa) Elongation (%) 645 557 568 648 640 Shore A hardness 60 61 59 62 62 Tear Tear strength (N/mm) 78.11 67.42 76.21 78.01 76.45 resistance Wear Akron abrasion (cm.sup.3) 0.13 0.13 0.20 0.14 0.13 resistance property Heat Final temperature (° C.) 59.4 59.7 73.9 61.2 60.4 generation in compression

(20) The following conclusions can be obtained based on Table 1.

(21) (1) A combination of a small amount of the W-type chloroprene rubber, the natural rubber, styrene-butadiene rubber and butadiene rubber would improve the tear resistance of the protective rubber track shoe for the excavator, and the tear resistance was improved by about 15%.

(22) (2) A combination of a small amount of the W-type chloroprene rubber, the natural rubber, styrene-butadiene rubber and butadiene rubber would improve the wear resistance of the protective rubber track shoe for the excavator, and the wear resistance was improved by about 35%.

(23) (3) The introduction of a small amount of the 120-mesh rubber powder would improve the processing performance of the rubber compound, and reduce the heat generation of the track shoe in compression. The final temperature of the rubber mix in the compression was reduced about 20%, and the wear resistance of the rubber mix was enhanced by about 35%.

(24) 2. Thermo-Oxidative Aging Resistance

(25) TABLE-US-00002 TABLE 2 Comparison of thermo-oxidative aging resistance of the protective rubber track shoes prepared in Examples 1-5 Experimental Example Example Example Example Example conditions Items 1 2 3 4 5 100° C. × 72 h Tensile Before aging 18.52 16.73 18.71 17.86 18.68 Thermo- strength After aging 17.36 15.89 17.23 15.24 16.14 oxidative (MPa) Aging −6 −5 −8 −15 14 aging test coefficient (%) Hardness Before aging 60 61 59 62 62 After aging 68 67 66 73 72 Variation +8 +6 +7 +11 +10 Outdoor 3 Months No No No Serious Serious exposure discoloration discoloration discoloration discoloration discoloration 6 Months Light Light Light Serious Serious discoloration discoloration discoloration discoloration discoloration 12 Months  Light Light Light Serious Serious discoloration discoloration discoloration discoloration discoloration

(26) The following conclusions can be drawn based on Table 2.

(27) (1) Using the new anti-aging agent 3100 in accompany with the pollution-free anti-aging agent CTU to replace the combination of the anti-aging agent 4010NA and the anti-aging agent D or the combination of the anti-aging agent 4010NA and the anti-aging agent 4020 would largely improve the thermo-oxidative aging resistance of the protective rubber track shoes. Specifically, in the thermo-oxidative aging tests under the same conditions, an absolute value of the aging coefficient was reduced by 40-50%.

(28) (2) Using the new anti-aging agent 3100 in accompany with the pollution-free anti-aging agent CTU to replace the combination of the anti-aging agent 4010NA and the anti-aging agent D or the combination of the anti-aging agent 4010NA and the anti-aging agent 4020 would hinder the discoloration of the protective rubber track shoes due to the fact that the new anti-aging agent 3100 has low volatility, extractability and mobility, and the pollution-free anti-aging agent CTU is non-polluting and low in coloring performance, and has low mobility.

(29) 3. Ozone Aging Resistance

(30) TABLE-US-00003 TABLE 3 Comparison of ozone aging resistance of the protective rubber track shoes prepared in Examples 1-5 Aging results The earliest time Aging for an appearance time Examples of crack (h) (h) Crack conditions Example 1 48 72 crack on one side, within 1 mm Example 2 52 crack on one side, within 1 mm Example 3 40 crack on both sides, more than 1-3 mm Example 4 20 a large number of cracks on both sides, no less than 3-5 mm Example 5 16 a large number of cracks on both sides, no less than 3-5 mm Note 1. Experimental conditions of ozone aging Ozone concentration: 200 ± 5 ppm; sample elongation: 20%; test temperature: 40 ± 2° C.; relative humidity: 60%; and ozone flow rate: 500 mL/min. 2. During the experiment, samples were observed every four hours to determine “the earliest crack” in the ozone aging.

(31) Table 3 showed the followings.

(32) Using the new anti-aging agent 3100 in accompany with the pollution-free anti-aging agent CTU to replace the combination of the anti-aging agent 4010NA and the anti-aging agent D or the combination of the anti-aging agent 4010NA and the anti-aging agent 4020 would improve the ozone aging resistance of protective rubber track shoes, and the time of resistance against ozone aging was extended by 2-3 times.

(33) 4. Flex Cracking Resistance

(34) TABLE-US-00004 TABLE 4 Comparison of flex cracking resistance of the protective rubber track shoes prepared in Examples 1-5 Phenomenon and degree of cracking The number Example Example Example Example Example of flex 1 2 3 4 5  50 thousand No crack No crack No crack No crack No crack  55 thousand No crack No crack No crack No crack No crack  60 thousand No crack No crack No crack No crack No crack  65 thousand No crack No crack No crack No crack No crack  70 thousand No crack No crack No crack No crack No crack  75 thousand No crack 6 pinprick- No crack No crack No crack like cracks, level 1  80 thousand No crack 3 cracks No crack No crack No crack within 0.5-1.0 mm, level 3  85 thousand No crack 5 cracks No crack No crack No crack within 1.0-1.5 mm, level 4  90 thousand No crack The largest No crack No crack No crack crack is greater than 3 mm. level 6  95 thousand No crack — No crack No crack No crack 100 thousand 2 — 9 8 5 pinprick- pinprick- pinprick- pinprick- like like like like cracks, cracks, cracks, cracks, level 1 level 1 level 1 level 1

(35) A combination of a small amount of the W-type chloroprene rubber, the natural rubber, styrene-butadiene rubber and butadiene rubber, with the new anti-aging agent 3100 in accompany with the pollution-free anti-aging agent CTU as a protection system, would improve the flex cracking resistance of the protective rubber track shoes. The number of the flexes that the protective rubber track shoe can resist was increased by 30-35,000, and the flex cracking resistance was increased by about 40%.

(36) 5. Others

(37) (1) The new anti-aging agent 3100 and the pollution-free anti-aging agent CTU, used as a protection system, reduced the rubber frost spray of protective rubber track shoe for the excavator.

(38) (2) A combination of a small amount of the W-type chloroprene rubber, the natural rubber, styrene-butadiene rubber and butadiene rubber would improve the flame retardancy of protective rubber crack shoe for the excavator.

(39) (3) When adhering to a creak plates, the protective rubber crack shoe prepared using a combination of a small amount of the W-type chloroprene rubber, the natural rubber styrene-butadiene rubber and butadiene rubber would increase the viscosity of a coating.

(40) (4) The rubber powder and reclaimed rubber used herein largely reduced the cost and improved the processing of the rubber compound for the protective rubber track shoe.