阅读说明：本技术 一种硫化粘接橡胶输送带的高强度半成品接头胶料 (High-strength semi-finished product joint sizing material for vulcanized bonded rubber conveying belt ) 是由 李耀辉 王怀金 徐艳 李记全 于 2021-07-30 设计创作，主要内容包括：本发明提供了一种硫化粘接橡胶输送带的高强度半成品接头胶料,所述接头胶料包括芯胶和覆盖胶。本发明的芯胶和覆盖胶具有极佳的机械性能和耐久性,并且芯胶与覆盖胶具有很好的黏合性。当应用于橡胶输送带中时,所述半成品接头胶料通过简单硫化即可生成具有所需特性的接头,从而将橡胶输送带牢牢粘接。因此,本发明的半成品接头胶料适合于工业化大规模使用。(The invention provides a high-strength semi-finished joint rubber material for a vulcanized and bonded rubber conveying belt. The core glue and the covering glue have excellent mechanical property and durability, and the core glue and the covering glue have good adhesion. When the semi-finished joint sizing material is applied to a rubber conveying belt, a joint with the required characteristics can be generated through simple vulcanization, and therefore the rubber conveying belt is firmly bonded. Therefore, the semi-finished joint compound is suitable for industrial large-scale use.)

1. A semi-finished joint sizing material for a vulcanized bonded rubber conveying belt comprises a core rubber, wherein the core rubber is prepared by mixing the following raw materials: 8-16 parts of natural rubber and/or smoked sheet rubber, 12-30 parts of styrene-butadiene rubber, 2-3 parts of zinc oxide, 0.4-1 part of stearic acid, 0.6-1.6 parts of an anti-aging agent, 0.05-0.16 part of a vulcanization accelerator ZDMC, 0.18-0.28 part of a vulcanization accelerator NOBS, 0.85-1.04 part of sulfur, 10-20 parts of carbon black, 3-8 parts of white carbon black, 1-5 parts of aromatic hydrogen oil, 0.25-0.6 part of a binder, 1.2-2.0 parts of cobalt naphthenate and 0.6-1.2 parts of bis (cyclopentadiene) cobalt.

2. The joint compound of claim 1, wherein the ratio of natural gum to smoked sheet gum in the core gum is 1: 0 to 0: 1.

3. the joint compound according to claim 1, wherein the vulcanization accelerator ZDMC in the core compound is 0.09-0.14 parts, and the vulcanization accelerator NOBS in the core compound is 0.20-0.26 parts; the ratio of the vulcanization accelerator ZDMC to the vulcanization accelerator NOBS is 1: 1.5 to 2.5.

4. The joint compound of claim 1, wherein the ratio of cobalt naphthenate to cobalt bis (cyclopentadienyl) is 1: 1.5 to 3.

5. The joint compound according to claim 1, wherein the semi-finished joint compound further comprises a cover rubber prepared by mixing the following raw materials: 11-20 parts of natural rubber, 11-20 parts of butadiene styrene rubber, 0.3-0.8 part of sulfur, 0.05-0.15 part of vulcanization accelerator ZDMC, 0.18-0.26 part of vulcanization accelerator NOBS, 1-2 parts of zinc oxide, 0.32-0.90 part of stearic acid, 0.25-0.31 part of paraffin, 2-4 parts of aromatic hydrogen oil, 6-24 parts of wear-resistant carbon black, 0.1-1 part of anti-aging agent, 1.5-4 parts of solid coumarone and 0.4-1.3 parts of coupling agent.

6. The joint compound according to claim 5, wherein the vulcanization accelerator ZDMC in the cover rubber is 0.09-0.13 parts, and the vulcanization accelerator NOBS in the cover rubber is 0.20-0.25 parts; the ratio of the vulcanization accelerator ZDMC to the vulcanization accelerator NOBS is 1: 1.5 to 2.5.

7. The joint compound according to claim 5, wherein the ratio of natural rubber to styrene butadiene rubber in the cover compound is 2: 1-1: 2.

8. the joint compound of claim 5, wherein the core and cap compounds are prepared by the following process: mixing the other materials except the sulfur and the vulcanization accelerator in an internal mixer, then transferring to an open mill, adding the sulfur and the vulcanization accelerator for mixing, and respectively preparing the core rubber and the cover rubber.

9. Use of a joint compound according to claim 5 in the vulcanised bonding of rubber belts to make joints, said use comprising using the core rubber as upper and lower core rubbers and the cover rubbers as upper and lower cover rubbers, which are co-formed with the rubber belt carcass at the joint to make the joint.

10. A method of vulcanization bonding a rubber conveyor belt, comprising: laminating an upper cover rubber derived from the cover rubber in the claim 5 and an upper core rubber derived from the core rubber in the claim 1, laminating a lower cover rubber derived from the cover rubber in the claim 5 and a lower core rubber derived from the core rubber in the claim 1 on a forming table, and then cold-pressing and forming the upper cover rubber, the upper core rubber, a rubber conveyer belt framework layer at a joint, the lower cover rubber and the lower core rubber to obtain a joint belt blank; and vulcanizing the joint strip blank.

Technical Field

The invention relates to the field of materials, in particular to a high-strength semi-finished joint sizing material for a vulcanized and bonded rubber conveying belt.

Background

The rubber conveyer belt is a main external accessory of the rubber belt conveyer and is mainly used for conveying solid materials of various enterprises such as mines, metallurgy, steel, coal, hydropower, building materials, chemical engineering, grain and the like. The rubber conveyer belt is a main component for dragging and bearing materials, and all the conveyer belts can be used only by being connected into a ring shape, so the service life of the conveyer belt and whether the conveyer belt can stably and smoothly run are directly influenced by the quality of a joint of the conveyer belt, and the connection problem must be reasonably solved by ensuring the normal running of the rubber belt and saving rubber. The connection method of the rubber conveyer belt can be divided into mechanical connection, vulcanization bonding, epoxy resin bonding and the like.

The mechanical connection has various forms, such as hook card connection, hinge connection, board card connection and lap riveting. The mechanical connection method has the advantages of simple connection tool, simple and convenient operation, quick joint and the like, and has the defects of the joint strength of only 40-50% of that of the adhesive tape, short service life, sand leakage at the joint, irregular joint and easy deviation, tearing of the adhesive tape when the clamp is tilted and the like, so that the mechanical connection method is mainly suitable for temporarily dismounting the belt. Each of these methods of mechanical attachment has its advantages, but neither method is as advantageous as the vulcanization bonding method, and efforts are made to avoid mechanical attachment unless it is a conveyor that requires frequent disassembly.

The vulcanization bonding method is to cut the cloth layer and the glue layer of the joint part of the adhesive tape into symmetrical differential levels according to a certain form and angle, apply semi-finished joint glue stock or coat glue slurry, then heat for a certain time under certain pressure and temperature conditions, and through vulcanization reaction, the raw rubber is changed into vulcanized rubber, so that the joint part obtains the best adhesive strength. The vulcanization bonding method has the advantages of high strength, good durability, adhesive tape saving, no abrasion between a joint and a carrier roller and a roller surface, stable operation, no vibration noise, capability of changing the operation condition of a bearing, great reduction of the conditions of sand leakage and adhesive tape tearing and the like, and has the defects of more tools required by the joint, complex process, long joint time, incapability of repairing leaks and the like.

The epoxy bonding method is a method of bonding tapes using epoxy as an adhesive. The epoxy resin is a bonding material with high strength, large bonding force, small shrinkage and good chemical stability. The epoxy resin bonding method has the advantages of vulcanization bonding, but the tool is lighter and simpler in process than vulcanization bonding, and meanwhile, the leaking holes can be repaired. However, the epoxy resin bonding method has a poor joint flexural property as compared with the vulcanization bonding method, and also has a lower tensile strength than the vulcanization bonding method, and the tape has a difficult surface seam treatment and a more toxic material.

Although the vulcanization bonding method is a more common rubber conveyor belt joint method, the method still has the defects of insufficient joint mechanical performance, insufficient durability and insufficient adhesiveness and the like in practical application. Therefore, there is an urgent need to find more semi-finished joint compounds for the vulcanized and bonded rubber conveyor belt.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a high-strength semi-finished joint rubber material for vulcanized rubber conveying belts, which has the advantages of good mechanical properties including strength, elongation at break and the like, good durability and good adhesiveness.

The joint rubber material of the vulcanized and bonded rubber conveying belt comprises core rubber, wherein the core rubber is prepared by mixing the following raw materials: 8-16 parts of natural rubber and/or smoked sheet rubber, 12-30 parts of styrene-butadiene rubber, 2-3 parts of zinc oxide, 0.4-1 part of stearic acid, 0.6-1.6 parts of an anti-aging agent, 0.05-0.16 part of a vulcanization accelerator ZDMC, 0.18-0.28 part of a vulcanization accelerator NOBS, 0.85-1.04 part of sulfur, 10-20 parts of carbon black, 3-8 parts of white carbon black, 1-5 parts of aromatic hydrogen oil, 0.25-0.6 part of a binder, 1.2-2.0 parts of cobalt naphthenate and 0.6-1.2 parts of bis (cyclopentadiene) cobalt.

In one embodiment of the present invention, the natural gum and/or the smoked sheet gum in the core gum is preferably 8 to 14 parts, and more preferably 10 to 12 parts.

Preferably, the natural gum and the smoked sheet gum can be mixed and used in any ratio, such as 1: 0 to 0: 1, e.g. 1: 0,1: 1 or 0: 1: . In the core glue, the natural glue and the smoked sheet glue are used in different proportions, and the performance change of the core glue is small.

In one embodiment of the present invention, the styrene-butadiene rubber in the core rubber is preferably 16 to 24 parts, and more preferably 18 to 20 parts.

In the invention, the natural rubber or the smoked sheet rubber and the styrene butadiene rubber are mixed for use in a specific comparison manner, so that the strength of the core rubber is improved. In the case of using only styrene-butadiene rubber, the core rubber has a problem of insufficient mechanical properties.

In one embodiment of the invention, the zinc oxide in the core rubber is preferably 2.2-2.8 parts, and more preferably 2.4-2.6 parts.

In one embodiment of the present invention, stearic acid in the core gum is preferably 0.6-0.8 parts.

In one embodiment of the invention, the anti-aging agent in the core gum is selected from one or more of anti-aging agent RD, anti-aging agent SP, anti-aging agent BLE, anti-aging agent 4020, and anti-aging agent MB. Preferably, the anti-aging agent is selected from one or more of anti-aging agent RD, anti-aging agent SP and anti-aging agent BLE, more preferably, the anti-aging agent is selected from a mixture of anti-aging agent RD, anti-aging agent SP and anti-aging agent BLE; wherein, 0.2 to 0.5 part, preferably 0.3 to 0.4 part, of the anti-aging agent RD, 0.1 to 0.4 part, preferably 0.2 to 0.3 part, of the anti-aging agent SP, and 0.3 to 0.7 part, preferably 0.4 to 0.5 part of the anti-aging agent BLE.

In one embodiment of the present invention, the vulcanization accelerator ZDMC is preferably 0.09 to 0.14 parts, more preferably 0.09, 0.10, 0.11, 0.12, 0.13 or 0.14 parts, in the core gum. The vulcanization accelerator NOBS in the core rubber is preferably 0.20 to 0.26 part, more preferably 0.20, 0.21, 0.22, 0.23, 0.24, 0.25 or 0.26 part.

Preferably, the ratio of the vulcanization accelerator ZDMC to the vulcanization accelerator NOBS is 1: 1.5 to 2.5, more preferably 1: 1.7 to 2.2, more preferably 1: 2. the synergistic effect is achieved by the matched use of the vulcanization accelerator ZDMC and the vulcanization accelerator NOBS, and the key effect is achieved on the improvement of the mechanical property and the durability of the core rubber.

In one embodiment of the present invention, the sulfur in the core rubber is preferably 0.80 to 1.00 parts, and more preferably 0.93 to 0.98 parts. Preferably, the sulfur is insoluble sulfur.

In one embodiment of the invention, the carbon black in the core rubber is preferably 15 to 20 parts; the white carbon black is preferably 4-6 parts, and more preferably 5-6 parts.

In one embodiment of the invention, the aromatic hydrogen oil in the core rubber is preferably 3-4 parts.

In one embodiment of the invention, the binder in the core glue is selected from the group consisting of binder A, preferably 0.35-0.45 parts.

In one embodiment of the invention, the cobalt naphthenate in the core gum is preferably 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0 parts; preferably, the cobalt naphthenate accounts for 1.8-2.0 parts.

In one embodiment of the invention, the bis (cyclopentadienyl) cobalt in the core gum is preferably 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 or 1.2 parts; preferably, the cobalt naphthenate accounts for 0.8-0.9 part.

Preferably, the ratio of cobalt naphthenate to cobalt bis (cyclopentadienyl) is 1: 1.5 to 3, more preferably 1: 2 to 2.5. The matching use of cobalt naphthenate and cobalt bis (cyclopentadiene) plays a synergistic effect, plays a key role in the core adhesive adhesiveness, and improves the durability to a certain extent.

In one embodiment of the invention, the joint compound of the vulcanized and bonded rubber conveying belt further comprises a covering rubber, wherein the covering rubber is prepared by mixing the following raw materials: 11-20 parts of natural rubber, 11-20 parts of butadiene styrene rubber, 0.3-0.8 part of sulfur, 0.05-0.15 part of vulcanization accelerator ZDMC, 0.18-0.26 part of vulcanization accelerator NOBS, 1-2 parts of zinc oxide, 0.32-0.90 part of stearic acid, 0.25-0.31 part of paraffin, 2-4 parts of aromatic hydrogen oil, 6-24 parts of wear-resistant carbon black, 0.1-1 part of anti-aging agent, 1.5-4 parts of solid coumarone and 0.4-1.3 parts of coupling agent.

In one embodiment of the present invention, the natural rubber in the cover rubber is preferably 13 to 16 parts, and more preferably 14 to 16 parts.

In one embodiment of the invention, the styrene-butadiene rubber in the covering rubber is preferably 13 to 16 parts, and more preferably 14 to 16 parts.

Preferably, in the present invention, the ratio of the natural rubber to the styrene-butadiene rubber is 2: 1-1: 2, more preferably 1: 1. 1: 1.5.

in one embodiment of the present invention, the sulfur in the cover rubber is preferably 0.4 to 0.7 parts, and more preferably 0.5 to 0.6 parts.

In one embodiment of the present invention, the vulcanization accelerator ZDMC is preferably 0.09 to 0.13 parts, more preferably 0.09, 0.10, 0.11, 0.12 or 0.13 parts, in the cover paste. The vulcanization accelerator NOBS in the cover rubber is preferably 0.20 to 0.25 part, more preferably 0.20, 0.21, 0.22, 0.23, 0.24 or 0.25 part.

Preferably, the ratio of the vulcanization accelerator ZDMC to the vulcanization accelerator NOBS is 1: 1.5 to 2.5, more preferably 1: 1.8 to 2.2, more preferably 1: 2. the synergistic effect is achieved by the matched use of the vulcanization accelerator ZDMC and the vulcanization accelerator NOBS, and the key effect is achieved on the improvement of the mechanical property and the durability of the rubber material.

In one embodiment of the invention, the zinc oxide in the covering glue is preferably 1.4-1.6.

In one embodiment of the present invention, stearic acid in the cover gel is preferably 0.6 to 0.8.

In one embodiment of the present invention, the paraffin wax in the cover glue is preferably 0.27 to 0.295.

In one embodiment of the invention, the aromatic hydrogen oil in the covering glue is preferably 2-3 parts.

In one embodiment of the present invention, the wear resistant carbon black in the cover rubber is preferably 12 to 18 parts, more preferably 14 to 16 parts. Preferably, the amount of the wear-resistant carbon black may be 30 to 60%, preferably 40 to 55%, more preferably 50 to 55% of the amount of the raw rubber, depending on the total amount of the raw rubber, i.e., the natural rubber and the styrene-butadiene rubber.

In one embodiment of the invention, the wear-resistant carbon black is selected from a mixture of medium super wear-resistant carbon black and high wear-resistant carbon black, wherein the ratio of the medium super wear-resistant carbon black to the high wear-resistant carbon black may be 0.5 to 3: 1, preferably 1-2: 1, more preferably 1.5 to 1.8: 1.

in one embodiment of the present invention, the antioxidant is preferably 0.2 to 0.9 parts, more preferably 0.45 to 0.62 parts, in the cover rubber. The anti-aging agent is selected from one or more of anti-aging agent D and anti-aging agent RD. Preferably, the antioxidant is selected from antioxidant D.

In one embodiment of the invention, the solid coumarone in the coating gum is preferably 2 to 3 parts.

In one embodiment of the present invention, the coupling agent is preferably 0.6 to 1.0 part, more preferably 0.7 to 0.9 part, in the cover glue. Preferably, the coupling agent comprises at least one of a titanate coupling agent and a silane coupling agent. More preferably, the coupling agent is at least one selected from silane coupling agent KH550 and silane coupling agent Si-69.

The invention also aims to provide a preparation method of the core glue and the cover glue, which comprises the following steps: mixing the other materials except the sulfur and the vulcanization accelerator in an internal mixer, then transferring to an open mill, adding the sulfur and the vulcanization accelerator for mixing, and respectively preparing the core rubber and the cover rubber.

Preferably, in the preparation of the core rubber, the rubber discharge temperature in an internal mixer is 120-130 ℃.

Preferably, in the preparation of the covering rubber, the rubber discharge temperature in an internal mixer is 130-140 ℃.

The invention also aims to provide an application of the semi-finished joint rubber material in vulcanization adhesion in a rubber conveying belt to manufacture a joint, wherein the application comprises the steps of taking the core rubber as an upper core rubber and a lower core rubber, taking the cover rubber as an upper cover rubber and a lower cover rubber, and jointly manufacturing the upper cover rubber and the lower cover rubber and a rubber conveying belt framework layer at the joint into the joint.

Preferably, the application comprises the steps of laminating and molding the upper cover rubber and the upper core rubber, and the lower cover rubber and the lower core rubber on a molding table, and then cold-pressing and molding the upper cover rubber, the upper core rubber, the rubber conveyer belt framework layer at the joint, the lower cover rubber and the lower core rubber to obtain a joint belt blank; and vulcanizing the joint strip blank.

Another object of the present invention is to provide a method for vulcanization bonding a rubber conveyor belt, comprising: laminating the upper cover rubber and the upper core rubber, and laminating the lower cover rubber and the lower core rubber on a forming table for forming, and then performing cold press forming on the upper cover rubber and the upper core rubber, the rubber conveyer belt framework layer at the joint, and the lower cover rubber and the lower core rubber to obtain a joint belt blank; and vulcanizing the joint strip blank.

Preferably, the rubber conveyor belt skeleton layer includes, but is not limited to, a steel wire rope, a steel wire mesh, a gauze layer, a fiber mesh, and the like.

In the present invention, unless otherwise specified, the "parts" are parts by weight and the proportions are proportions by weight.

Has the advantages that:

the invention provides a high-strength semi-finished joint rubber material for a vulcanized and bonded rubber conveying belt, which comprises core rubber and covering rubber. The core glue and the covering glue have excellent mechanical performance and durability and have excellent adhesion property by properly combining the components of the core glue and the covering glue. When the semi-finished joint sizing material is applied to a rubber conveying belt, a joint with the required characteristics can be generated through simple vulcanization, and therefore the rubber conveying belt is firmly bonded. Therefore, the semi-finished joint compound of the present invention is suitable for industrial applications.

Detailed Description

Hereinafter, preferred examples of the invention will be described in detail. The examples are given for the purpose of better understanding the inventive content and are not intended to be limiting. Insubstantial modifications and adaptations of the embodiments in accordance with the present disclosure remain within the scope of the invention.

Example (b):

firstly, a core rubber mixing process:

preparation before dosing

The block-shaped and coarse-grained compounding agents are crushed and ground, and dried to remove or reduce water and volatile impurities in the compounding agents, wherein the drying temperature is 25-40 ℃ lower than the melting point temperature of the compounding agents so as to avoid melting and blocking.

(II) weighing according to the formula

(III) kneading

(1) Starting an air pump in a 75L internal mixer at the rotating speed of 30 revolutions per minute, lifting a top plug, adding raw rubber (natural rubber/smoked sheet rubber and styrene-butadiene rubber) and stirring for 10 seconds, then adding small medicines (zinc oxide, stearic acid, an anti-aging agent and cobalt salt) and stirring for 10 seconds, then adding carbon black and white carbon black, dropping the top plug for 1 minute to 1.5 minutes, lifting the top plug, adding aromatic hydrogen oil and a binder A, and discharging the rubber at the specified rubber discharge temperature (130 ℃);

(2) and (3) after rubber is discharged, turning the mill, adjusting the roller spacing to 6mm, cooling the rubber material for 3-4 times from a roller gap falling plate, cooling to below 90 ℃, adding a vulcanization accelerator and sulfur for 2 times, rolling 2-3 after eating, packaging 4, and cooling, drying and stacking the lower piece on a hanging rack dipped with a separant.

The respective examples and comparative example formulations are shown in table 1:

table 1: core rubber example and comparative example formulations

Secondly, a covering rubber mixing process:

preparation before dosing

The block-shaped and coarse-grained compounding agents are crushed and ground, and dried to remove or reduce water and volatile impurities in the compounding agents, wherein the drying temperature is 25-40 ℃ lower than the melting point temperature of the compounding agents so as to avoid melting and blocking.

(II) weighing according to the formula

(III) kneading

(1) Starting an air pump in a 75L internal mixer at the rotating speed of 30 r/min, lifting a top plug, adding raw rubber (natural rubber and butadiene styrene rubber) and stirring for 10 seconds, then adding small medicines (zinc oxide, stearic acid, an anti-aging agent, solid coumarone and a coupling agent) and stirring for 10 seconds, then adding wear-resistant carbon black, dropping the top plug for 1-1.5 minutes, lifting the top plug, adding aromatic hydrogen oil and paraffin, and discharging the rubber at the specified rubber discharge temperature (140 ℃);

(2) and (3) after rubber is discharged, turning the mill, adjusting the roller distance to 8mm, cooling the rubber material for 3-4 times from a roller gap falling plate, cooling to below 100 ℃, adding vulcanization accelerators (the vulcanization accelerators ZDMC and the vulcanization accelerator NOBS) and sulfur for 2 times, rolling for 2-3 times after eating, packaging for 4 times, and cooling, drying and stacking the lower piece by dipping the release agent hanger.

The respective examples and comparative example formulations are shown in table 2:

table 2: coverlay adhesive examples and comparative example formulations

Raw materials (kg)	Example 5	Example 6	Example 7	Comparative example 6	Comparative example 7
						National standard No. 2 natural rubber	14.28	14.28	11.42	14.28	14.28
Styrene-butadiene rubber 1500	14.28	14.28	17.14	14.28	14.28
						Insoluble sulfur	0.6	0.6	0.6	0.6	0.6
Vulcanization accelerator ZDMC	0.12	0.10	0.12	0.36
						Accelerant NOBS	0.24	0.20	0.22	-	0.36
Zinc oxide	1.43	1.43	1.43	1.43	1.43
						Stearic acid	0.71	0.71	0.71	0.71	0.71
Paraffin (semi-extract)	0.285	0.285	0.285	0.285	0.285
						Aromatic hydrogen oil	2.57	2.57	2.57	2.57	2.57
Medium and super wear-resistant carbon black N220	8.57	8.57	8.57	8.57	8.57
						Highly wear-resistant carbon black N330	5.71	5.71	5.71	5.71	5.71
Anti-aging agent D	0.57	0.57	0.57	0.57	0.57
						Solid coumarone	2.57	2.57	2.57	2.57	2.57
Silane coupling agent KH550	0.81	0.81	0.81	0.81	0.81

Thirdly, preparing a joint: laminating the upper cover rubber and the upper core rubber, and laminating the lower cover rubber and the lower core rubber on a forming table for forming, and then performing cold press forming on the upper cover rubber and the upper core rubber, the rubber conveyer belt framework layer at the joint, and the lower cover rubber and the lower core rubber to obtain a joint belt blank; and then placing the joint strip blank on a flat vulcanizing machine for vulcanization, wherein the vulcanization temperature is 150 ℃, the vulcanization pressure is 15MPa, and cooling to obtain the joint.

The respective examples and comparative example formulations are shown in table 3:

table 3: joint example and comparative example formulations

Raw material

Application example 1

Application example 2

Application example 3

Comparative application example 1

Comparative application example 2

Comparative application example 3

Comparative application example 4

Upper covering glue

Example 5

Example 6

Example 7

Example 5

Example 5

Example 6

Example 7

Core glue

Example 1

Example 2

Example 4

Comparative example 3

Comparative example 4

Comparative example 3

Comparative example 4

Lower core glue

Example 1

Example 2

Example 4

Comparative example 3

Comparative example 4

Comparative example 3

Comparative example 4

Lower covering glue

Example 5

Example 6

Example 7

Example 5

Example 5

Example 6

Example 7

Fourthly, performance test

Tensile strength: the tensile strength of the core and cover glues was tested according to GB/T528-.

Elongation at break: the elongation at break of the core and cover glues was tested according to GB/T528-.

Hot air aging test: the hot air aging test of the core glue and the cover glue is tested according to GB/T3512-.

Abrasion loss: the wear of the cover layer was tested according to GB/T1689-.

Adhesive strength: the adhesive strength of the core adhesive layer and the cover layer was tested according to GB/T6759-2013.

The test results are shown in tables 4 and 5, and each result is expressed as an average value.

Table 4: results of mechanical Property testing

Table 5: adhesive strength test results

	Adhesive strength/N/mm2
		Application example 1	21.3
Application example 2	20.6
		Application example 3	19.7
Comparative application example 1	12.6
		Comparative application example 2	14.5
Comparative application example 3	11.8
		Comparative application example 4	13.0

As shown by the test results, the semi-finished joint compound of the present invention has excellent mechanical properties and durability for both the core glue and the cover glue, and has excellent adhesion between the core glue and the cover glue. Particularly, the vulcanization accelerator ZDMC and the accelerator NOBS act together, so that the mechanical properties and durability of the core rubber and the covering rubber are obviously improved; the cobalt naphthenate and the cobalt bis (cyclopentadiene) act together, so that the adhesive strength between the core glue and the covering glue is obviously improved, and the durability of the core glue is improved to a certain extent.

Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.