CN111793349A

CN111793349A - Polyurethane cover rubber, conveying belt prepared from cover rubber and preparation method of conveying belt

Info

Publication number: CN111793349A
Application number: CN202010762558.9A
Authority: CN
Inventors: 杜新长; 杜明华; 周豪杰
Original assignee: Shandong Phoebus Rubber Co ltd
Current assignee: Shandong Phoebus Rubber Co ltd
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2020-10-20

Abstract

The invention belongs to the technical field of rubber molding. The invention provides a polyurethane cap rubber, wherein different modifiers are added into raw polyurethane rubber to improve the performance of the polyurethane rubber, so that on the premise of improving the oil resistance, excellent wear resistance is still maintained, and the application range of the polyurethane rubber is wider; meanwhile, a methyl-white system is added, so that the modified polyurethane rubber can be better adhered to cord fabrics or steel wires, separation in use is prevented, and the quality of products is ensured. The invention also provides a preparation method of the conveyer belt, which comprises the steps of independently banburying the cap rubber and the adhesive tape, and then controlling the size of the banburied cap rubber and the adhesive tape through a calendering process, so that the banburied cap rubber and the adhesive tape can be fully attached to a framework material to obtain a semi-finished product; finally, the wear-resistant and oil-resistant polyurethane conveyor belt is obtained through a corresponding vulcanization process. The invention improves the quality of the conveyer belt and ensures the use in the conveying process by a simple production process.

Description

Polyurethane cover rubber, conveying belt prepared from cover rubber and preparation method of conveying belt

Technical Field

The invention relates to the technical field of rubber molding, in particular to polyurethane cover rubber, a conveying belt prepared from the cover rubber and a preparation method of the conveying belt.

Background

The conveyer belt is a composite product of rubber, fiber and metal or a composite product of plastic and fabric for carrying and conveying materials in conveying. The conveyer belt is widely applied to occasions with short conveying distance and small conveying amount in the industries of cement, coking, metallurgy, chemical industry, steel and the like. However, the conveyor belt is easily worn due to long-time working, and the conveyor belt is prematurely scrapped due to continuous use in such a situation.

Therefore, in order to increase the working time of the conveyor belt, the polyurethane rubber is placed on the more wear-resistant polyurethane rubber, but when the polyurethane rubber is used as the material of the conveyor belt, the polyurethane rubber is difficult to use in a severe environment due to poor oil resistance; after the polyurethane is modified, although the oil resistance is changed, the wear resistance is equal to that of common materials, and the wear resistance and the oil resistance of the polyurethane cannot be simultaneously maintained.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a polyurethane cover rubber, a conveying belt prepared from the cover rubber and a preparation method of the conveying belt.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a polyurethane cover adhesive which is prepared from the following raw materials in parts by weight: 90-110 parts of polyurethane crude rubber, 2-4 parts of a vulcanizing agent, 1-3 parts of an accelerator, 1-3 parts of an active agent, 30-40 parts of a reinforcing agent, 1-5 parts of a coupling agent, 0.5-3 parts of a release agent, 2-10 parts of a plasticizer, 0.5-8 parts of an anti-aging agent and 16-25 parts of a m-methylene system.

Preferably, the accelerator is dibenzothiazyl disulfide and/or 2-mercaptobenzothiazole, and when the dibenzothiazyl disulfide and the 2-mercaptobenzothiazole are simultaneously contained, the mass ratio of the dibenzothiazyl disulfide to the 2-mercaptobenzothiazole is (1-2): (1-2).

Preferably, the reinforcing agent is carbon black and/or white carbon, and when the reinforcing agent contains carbon black and white carbon, the mass ratio of the carbon black to the white carbon is (1-5): (30-35);

the coupling agent is gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane or gamma-aminoethylaminopropyltrimethoxysilane.

Preferably, the plasticizer is dioctyl phthalate, chlorinated paraffin or diphenyl phosphate;

the anti-aging agent is 4, 4' -bis (alpha, alpha-dimethylbenzyl) diphenylamine, 2-mercaptobenzimidazole or 2, 2, 4-trimethyl-1, 2-dihydroquinoline polymer;

the m-methylene white system comprises resorcinol, hexamethylenetetramine and white carbon black, wherein the mass ratio of the resorcinol to the hexamethylenetetramine to the white carbon black is (2.5-3.8): (1.5-2.5): (12-18).

The invention also provides a conveyor belt prepared from the polyurethane cover rubber, and the conveyor belt comprises the polyurethane cover rubber, a bonding rubber and a framework material, wherein the mass ratio of the polyurethane cover rubber to the bonding rubber to the framework material is (40-90): (9-30): (5-25).

Preferably, the rubberizing comprises natural rubber, styrene-butadiene rubber and polyurethane raw rubber, wherein the mass ratio of the natural rubber to the styrene-butadiene rubber to the polyurethane raw rubber is (1-5): (5-9): (1-5).

The invention also provides a preparation method of the conveyer belt, which comprises the following steps:

(1) banburying polyurethane cover rubber to obtain banburying cover rubber;

(2) banburying the rubberizing to obtain banburying rubberizing;

(3) sequentially calendering and thermally laminating the banburying cover rubber, the banburying adhesive and the framework material to obtain a semi-finished product;

(4) and vulcanizing the semi-finished product to obtain the conveying belt.

Preferably, the banburying in the step (1) is a first banburying step and a second banburying step which are sequentially carried out, wherein the banburying pressure is 0.5-0.7 MPa;

the rotation speed of the first banburying step is 30-35 rpm, the time of the first banburying step is 180-240 s, and the temperature of the first banburying step is less than or equal to 110 ℃;

the rotation speed of the second banburying step is 15-20 rpm, the time of the second banburying step is 120-160 s, and the temperature of the second banburying step is less than or equal to 90 ℃.

Preferably, the banburying time in the step (2) is 160-200 s, the banburying pressure is 0.4-0.8 MPa, and the banburying temperature is less than or equal to 105 ℃;

the temperature of calendering in the step (3) is 50-70 ℃, and the speed ratio of the calendered rubberized fabric to be calendered is (0.9-1.1): (1.3-1.5): (1.3-1.5): (0.9 to 1.1);

and (4) the temperature of the hot bonding in the step (3) is 50-60 ℃.

Preferably, the vulcanization pressure in the step (4) is 1.7-1.9 MPa, the vulcanization time is 20-50 min, and the vulcanization temperature is 130-160 ℃.

The invention provides a polyurethane cap rubber, wherein a vulcanizing agent, an accelerator, an activator, a reinforcing agent, a coupling agent, a release agent, a plasticizer and an anti-aging agent are added into a polyurethane raw rubber, so that the performance of the polyurethane rubber is improved, and on the premise of improving the oil resistance, excellent wear resistance is still kept, so that the application range of the polyurethane rubber is wider; meanwhile, a methyl-white system is added, so that the modified polyurethane rubber can be better adhered to cord fabrics or steel wires, separation in use is prevented, and the quality of products is ensured.

The invention also provides a conveyer belt prepared by using the polyurethane cover rubber, which mainly comprises the polyurethane cover rubber, the adhesive and a framework material; the polyurethane rubber is added into the rubberizing, so that synchronous vulcanization of the cover rubber and the rubberizing is achieved, compatibility among different formulas is improved, and the purpose of improving bonding strength is achieved.

The invention also provides a preparation method of the conveyer belt, which comprises the steps of independently carrying out banburying on the cover rubber and the rubberizing rubber, wherein the first banburying step and the second banburying step are sequentially carried out on the cover rubber to ensure that the auxiliary agent is fully dispersed into the polyurethane rubber; then, by a calendering process, the size of the cap rubber and the rubberizing rubber after banburying is controlled, and the semi-finished product can be fully attached to the framework material to obtain a semi-finished product; finally, the wear-resistant and oil-resistant polyurethane conveyor belt is obtained through a corresponding vulcanization process. The invention improves the quality of the conveyer belt and ensures the use in the conveying process by a simple production process.

Detailed Description

In the invention, the polyurethane raw rubber is 90-110 parts, preferably 95-105 parts, and more preferably 98-102 parts.

In the invention, the vulcanizing agent is 2-4 parts, preferably 2.2-3.8 parts, and more preferably 2.5-3.5 parts.

In the present invention, the vulcanizing agent is preferably sulfur.

In the invention, the accelerator is 1-3 parts, preferably 1.2-2.8 parts, and more preferably 1.8-2.2 parts.

In the invention, the accelerator is preferably dibenzothiazyl Disulfide (DM) and/or 2-mercaptobenzothiazole (M), and when the dibenzothiazyl disulfide and the 2-mercaptobenzothiazole are simultaneously contained, the mass ratio of the dibenzothiazyl disulfide to the 2-mercaptobenzothiazole is preferably (1-2): (1-2), more preferably (1.2-1.8): (1.2-1.8), more preferably (1.4-1.6): (1.4-1.6).

In the invention, when the rubber is vulcanized, the specific accelerator can accelerate the vulcanization speed, shorten the vulcanization time, reduce the vulcanization temperature, reduce the consumption of the vulcanizing agent and improve the physical and mechanical properties of the rubber.

In the invention, the active agent is 1-3 parts, preferably 1.2-2.8 parts, and more preferably 1.7-2.3 parts.

In the present invention, the active agent is preferably zinc stearate.

In the invention, the specific activator is used for activation, so that the using amount of the accelerator can be reduced, the vulcanization time can be shortened, and the vulcanization efficiency can be improved. In addition, zinc stearate can also play a role in thermal stabilization and prevent scorching.

In the present invention, the reinforcing agent is 30 to 40 parts, preferably 32 to 38 parts, and more preferably 34 to 36 parts.

In the invention, the reinforcing agent is preferably carbon black and/or white carbon black, and when the reinforcing agent contains carbon black and white carbon black at the same time, the mass ratio of the carbon black to the white carbon black is preferably (1-5): (30-35), more preferably (2-4): (31-34), more preferably (2.5-3.5): (32-33).

In the present invention, the carbon black preferably contains N220, N330, N375 or N550, more preferably N220 and N330.

In the invention, the reinforcing effect of the white carbon black is better than that of the carbon black, but the strength of the rubber is obviously improved under the matching action of the two substances.

In the invention, the coupling agent is 1-5 parts, preferably 2-4 parts, and more preferably 2.5-3.5 parts.

In the present invention, the coupling agent is preferably γ -aminopropyltriethoxysilane (KH550), γ - (2, 3-epoxypropoxy) propyltrimethoxysilane (KH560) or γ -aminoethylaminopropyltrimethoxysilane (KH 792).

In the invention, material interfaces with greatly different properties can be coupled through a specific coupling agent, so that the performance of rubber is improved, the bonding strength is increased, and the polyurethane cover rubber with excellent and reliable performance is obtained.

In the invention, the release agent is 0.5-3 parts, preferably 1-2 parts, and more preferably 1.4-1.6 parts; the addition of the release agent can reduce the stress between the mold and the rubber, and is convenient for demolding, and the release agent is well known to those skilled in the art.

In the present invention, the plasticizer is 2 to 10 parts, preferably 3 to 9 parts, and more preferably 5 to 7 parts.

In the present invention, the plasticizer is preferably dioctyl phthalate, chlorinated paraffin or diphenyl phosphate.

In the invention, the plasticizer is added to effectively increase the flexibility of the rubber, so that the vulcanized rubber is easy to process.

In the present invention, the antioxidant is 0.5 to 8 parts, preferably 2 to 6 parts, and more preferably 3 to 5 parts.

In the present invention, the antioxidant is preferably 4, 4' -bis (. alpha.,. alpha. -dimethylbenzyl) diphenylamine (445), 2-Mercaptobenzimidazole (MB), or 2, 2, 4-trimethyl-1, 2-dihydroquinoline polymer (RD).

In the invention, the addition of the antioxidant can delay the aging of the polyurethane rubber, inhibit the action of heat, light and oxidation of the rubber during storage, and prevent the phenomena of stickiness, hardening, brittleness, cracking and the like.

In the invention, the methyl system is 16-25 parts, preferably 18-23 parts, and more preferably 20-21 parts.

In the invention, the m-methylene white system preferably comprises resorcinol, hexamethylenetetramine and white carbon black, and the mass ratio of the resorcinol to the hexamethylenetetramine to the white carbon black is preferably (2.5-3.8): (1.5-2.5): (12-18), more preferably (2.8-3.5): (1.7-2.3): (13-17), more preferably (3-3.3): (1.9-2.1): (14-16).

In the invention, the metamethylene system generates resin reaction in the vulcanization process to form a characteristic resin network, and the characteristic resin network and the vulcanized rubber network structure form an interpenetrating structure to form a covalent bond, thereby enhancing the strength of the vulcanized rubber and the adhesive force of the rubber and the framework material.

The invention also provides a conveyor belt prepared from the polyurethane cover rubber, and the conveyor belt comprises the polyurethane cover rubber, a bonding rubber and a framework material, wherein the mass ratio of the polyurethane cover rubber to the bonding rubber to the framework material is (40-90): (9-30): (5-25), preferably (45-85): (12-27): (10-20), more preferably (50-80): (16-23): (12-18), more preferably (60-70): (18-21): (14-16).

In the invention, the rubberizing preferably comprises natural rubber, styrene-butadiene rubber and polyurethane raw rubber, and the mass ratio of the natural rubber, the styrene-butadiene rubber and the polyurethane raw rubber is preferably (1-5): (5-9): (1-5), more preferably (2-4): (6-8): (2-4), more preferably (2.5-3.5): (6.5-7.5): (2.5-3.5).

In the invention, the polyurethane rubber is added into the rubberizing, so that the synchronous vulcanization of the cap rubber and the rubberizing is realized, the compatibility among different formulas is improved, and the purpose of improving the bonding strength is achieved.

In the present invention, the framework material is preferably a cord or a steel wire, and more preferably a steel wire.

(1) banburying polyurethane cover rubber to obtain banburying cover rubber;

(2) banburying the rubberizing to obtain banburying rubberizing;

(4) and vulcanizing the semi-finished product to obtain the conveying belt.

In the present invention, the internal mixing in step (1) is preferably a first internal mixing and a second internal mixing which are sequentially performed, and the internal mixing pressure is preferably 0.5 to 0.7MPa, more preferably 0.55 to 0.65MPa, and even more preferably 0.58 to 0.62 MPa.

In the invention, the rotation speed of the first banburying step is preferably 30-35 rpm, more preferably 31-34 rpm, and more preferably 32-33 rpm; the first banburying step preferably lasts for 180-240 s, more preferably 190-230 s, and even more preferably 200-220 s; the temperature of the first banburying is preferably 110 ℃ or lower, more preferably 100 ℃ or lower, and still more preferably 95 ℃ or lower.

In the invention, the first step of banburying is to add polyurethane raw rubber, a vulcanizing agent, an accelerator and an activator.

In the invention, after the first banburying step is finished, the rest polyurethane cover rubber raw materials are added, and the second banburying step is started.

In the invention, the rotation speed of the second banburying step is preferably 15-20 rpm, more preferably 16-19 rpm, and more preferably 17-18 rpm; the second banburying step preferably lasts for 120-160 s, more preferably 130-150 s, and even more preferably 135-145 s; the temperature of the second banburying is preferably 90 ℃ or lower, more preferably 85 ℃ or lower, and still more preferably 80 ℃ or lower.

In the invention, the polyurethane rubber emits more heat during banburying, so that the glue filling amount can be properly reduced, and the filling coefficient of the glue filling amount is preferably 0.8-0.9, and more preferably 0.82-0.88.

In the invention, the banburying time in the step (2) is preferably 160-200 s, more preferably 170-190 s, and even more preferably 175-185 s; the banburying pressure is preferably 0.4-0.8 MPa, more preferably 0.5-0.7 MPa, and more preferably 0.55-0.65 MPa; the banburying temperature is preferably not more than 105 ℃, more preferably not more than 100 ℃, and more preferably not more than 90 ℃;

in the invention, the temperature of the rolling in the step (3) is preferably 50-70 ℃, more preferably 55-65 ℃, and more preferably 58-62 ℃; the speed ratio of the calendered rubberized fabric is preferably (0.9-1.1): (1.3-1.5): (1.3-1.5): (0.9 to 1.1); more preferably (0.95 to 1.05): (1.35-1.45): (1.35-1.45): (0.95-1.05).

In the invention, the framework material and the rubberizing speed are slow and synchronous, and are positioned at the central part of the conveying belt; the upper layer and the lower layer of hot laminating cover rubber have the same speed and are faster relative to the framework material, the polyurethane cover rubber is formed up and down, and the center is a conveyer belt structure with the laminating rubber surrounding the framework material.

In the invention, the temperature of the heat bonding in the step (3) is preferably 50-60 ℃, more preferably 52-58 ℃, and even more preferably 54-56 ℃.

In the invention, the vulcanizing pressure in the step (4) is preferably 1.7-1.9 MPa, more preferably 1.75-1.85 MPa, and more preferably 1.78-1.82 MPa, and the vulcanizing time is preferably 20-50 min, more preferably 25-45 min, and more preferably 30-40 min; the vulcanization temperature is preferably 130-160 ℃, more preferably 135-155 ℃, and even more preferably 140-150 ℃.

In the invention, the polyurethane rubber macromolecules are subjected to chemical reaction with sulfur under heating through a vulcanization process, and are crosslinked into a three-dimensional network structure, so that the polyurethane rubber has industrial use value.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.

Example 1

The polyurethane cover adhesive is prepared from the following raw materials in parts by mass: 100 parts of polyurethane crude rubber, 3 parts of sulfur, 2 parts of accelerator DM, 2 parts of zinc stearate, 35 parts of reinforcing agent, 3 parts of coupling agent KH550, 2 parts of release agent, 4 parts of dioctyl phthalate, 4 parts of anti-aging agent MB, and 20 parts of m-methylene system;

wherein, the reinforcing agent contains carbon black and white carbon black, the type of the carbon black is N330, and the mass ratio of the carbon black to the white carbon black is 2: 32.

the mass ratio of resorcinol, hexamethylenetetramine and white carbon black in the m-methylene white system is 3: 2: 15.

the conveyer belt prepared from the polyurethane cover rubber in the embodiment comprises the following raw materials, wherein the mass ratio of the polyurethane cover rubber, the rubberizing and the steel wire prepared in the embodiment is 45: 25: 25.

in the present embodiment, the topping comprises natural rubber, styrene-butadiene rubber, and polyurethane raw rubber; the mass ratio of the natural rubber, the styrene-butadiene rubber and the polyurethane crude rubber is 3: 7: 3.

the conveying belt provided in the embodiment is prepared by the following method: firstly, banburying polyurethane cover rubber: feeding polyurethane crude rubber, sulfur, an accelerator DM and zinc stearate into an internal mixer, setting the internal mixing pressure to be 0.6MPa, and internally mixing for 210s at the rotating speed of 33rpm and the temperature of 105 ℃; and then adding the rest raw materials, adjusting the banburying rotation speed to be 18rpm, and banburying temperature to be 90 ℃, and banburying for 140s to obtain the banburying cover rubber.

Banburying and rubberizing: the natural rubber, the styrene butadiene rubber and the polyurethane crude rubber are put into an internal mixer. And setting the banburying pressure at 0.6MPa and the banburying temperature at 90 ℃ for banburying for 160s to obtain the banburying rubberizing.

Placing the banburying rubberizing, the banburying cap rubberizing and the steel wire in a calender, controlling the calendering temperature to be 60 ℃, calendering the banburying rubberizing into a sheet shape, coating the steel wire, placing the steel wire at the central position of the sheet banburying rubberizing, thermally laminating the banburying rubberizing calendered into the sheet shape outside the sheet banburying rubberizing at the temperature of 60 ℃, and coating the banburying rubberizing to obtain a semi-finished product; wherein, the upper surface is covered with glue: banburying and rubberizing: steel wire: the speed ratio of the lower surface cover rubber is 1.4: 1: 1: 1.4.

and vulcanizing the semi-finished product at 1.8MPa and 145 ℃ for 35 minutes to obtain the conveyer belt.

The polyurethane cap rubber in this example was vulcanized at 150 ℃ and 2.0MPa for 30min, and the vulcanization characteristics are shown in Table 1.

The physical properties of the vulcanized polyurethane cover rubber in this example were tested, and the test results are recorded in table 2.

The conveyer belt of this example was subjected to a physical property test, and the test results are recorded in table 3.

Example 2

The polyurethane cover adhesive is prepared from the following raw materials in parts by mass: 90 parts of polyurethane crude rubber, 2 parts of sulfur, 2 parts of accelerator M, 1 part of zinc stearate, 30 parts of reinforcing agent, 2 parts of coupling agent KH550, 1 part of release agent, 3 parts of chlorinated paraffin, 2 parts of anti-aging agent RD and 18 parts of metacarpal white system;

wherein, the reinforcing agent contains carbon black and white carbon black, the type of the carbon black is N375, and the mass ratio of the carbon black to the white carbon black is 2: 30.

the mass ratio of resorcinol, hexamethylenetetramine and white carbon black in the m-methylene white system is 2.6: 1.8: 14.

The conveyer belt prepared from the polyurethane cover rubber in the embodiment comprises the following raw materials, and the mass ratio of the polyurethane cover rubber, the rubberizing and the steel wire prepared in the embodiment is 40: 20: 25.

in the present embodiment, the topping comprises natural rubber, styrene-butadiene rubber, and polyurethane raw rubber; the mass ratio of the natural rubber, the styrene-butadiene rubber and the polyurethane crude rubber is 2: 6: 2.

the conveying belt provided in the embodiment is prepared by the following method: firstly, banburying polyurethane cover rubber: the polyurethane crude rubber, the sulfur, the accelerator DM and the zinc stearate are put into an internal mixer, the internal mixing pressure is set to be 0.5MPa, and the internal mixing is carried out for 190s at the rotating speed of 32rpm and the temperature of 110 ℃; and then adding the rest raw materials, adjusting the banburying rotation speed to be 15rpm, and banburying temperature to be 85 ℃, and banburying for 120s to obtain the banburying cover rubber.

Banburying and rubberizing: the natural rubber, the styrene butadiene rubber and the polyurethane crude rubber are put into an internal mixer. And setting the banburying pressure at 0.55MPa and the banburying temperature at 85 ℃, and banburying for 170s to obtain the banburying rubberizing.

Placing the banburying rubberizing, the banburying cap rubberizing and the steel wire in a calender, controlling the calendering temperature to be 50 ℃, calendering the banburying rubberizing into a sheet shape, coating the steel wire, placing the steel wire at the central position of the sheet banburying rubberizing, thermally laminating the banburying rubberizing calendered into the sheet shape outside the sheet banburying rubberizing at the temperature of 60 ℃, and coating the banburying rubberizing to obtain a semi-finished product; wherein, the upper surface is covered with glue: banburying and rubberizing: steel wire: the speed ratio of the lower surface cover rubber is 1.4: 1: 1: 1.4.

and vulcanizing the semi-finished product at 1.8MPa and 145 ℃ for 40 minutes to obtain the conveyer belt.

The conveyer belt prepared in this example was subjected to a physical property test, and the test results are recorded in table 3.

Example 3

The polyurethane cover adhesive is prepared from the following raw materials in parts by mass: 105 parts of polyurethane crude rubber, 3 parts of sulfur, 2 parts of accelerator DM, 2 parts of zinc stearate, 38 parts of reinforcing agent, 4 parts of coupling agent, 1.5 parts of release agent, 4 parts of diphenyl phosphate, 2 parts of anti-aging agent MB and 23 parts of m-cresol white system;

wherein, the reinforcing agent contains carbon black and white carbon black, the type of the carbon black is N220, and the mass ratio of the carbon black to the white carbon black is 1: 32.

the mass ratio of resorcinol, hexamethylenetetramine and white carbon black in the m-methylene white system is 3: 1.5: 18.

the conveyer belt prepared from the polyurethane cover rubber in the embodiment comprises the following raw materials, and the mass ratio of the polyurethane cover rubber, the rubberizing and the steel wire prepared in the embodiment is 60: 30: 20.

in the present embodiment, the topping comprises natural rubber, styrene-butadiene rubber, and polyurethane raw rubber; the mass ratio of the natural rubber, the styrene-butadiene rubber and the polyurethane crude rubber is 2: 7: 3.

the conveying belt provided in the embodiment is prepared by the following method: firstly, banburying polyurethane cover rubber: feeding polyurethane crude rubber, sulfur, an accelerator DM and zinc stearate into an internal mixer, setting the internal mixing pressure to be 0.7MPa, and internally mixing for 200s at the rotating speed of 34rpm and the temperature of 100 ℃; and then adding the rest raw materials, adjusting the banburying rotation speed to be 16rpm, and banburying temperature to be 90 ℃, and banburying for 150s to obtain the banburying cover rubber.

Banburying and rubberizing: the natural rubber, the styrene butadiene rubber and the polyurethane crude rubber are put into an internal mixer. Setting the banburying pressure at 0.6MPa and the banburying temperature at 90 ℃, and banburying for 180s to obtain the banburying rubberizing.

Placing the banburying rubberizing, the banburying cap rubberizing and the steel wire in a calender, controlling the calendering temperature to be 55 ℃, calendering the banburying rubberizing into a sheet shape, coating the steel wire, placing the steel wire at the central position of the sheet banburying rubberizing, thermally laminating the banburying rubberizing calendered into the sheet shape outside the sheet banburying rubberizing at 65 ℃, and coating the banburying rubberizing to obtain a semi-finished product; wherein, the upper surface is covered with glue: banburying and rubberizing: steel wire: the speed ratio of the lower surface cover rubber is 1.4: 1: 1: 1.4.

vulcanizing the semi-finished product at 1.9MPa and 155 ℃ for 35 minutes to obtain the conveyer belt.

Table 1 example 1 polyurethane capstock vulcanization characteristics

Vulcanization characteristics	ML/N.m	MH/N.m	ts2/min	tc10/min	tc90/min
							0.012	0.267	13:08	5:31	15:58

TABLE 2 polyurethane capstock physical Properties

TABLE 3 conveyer belt physical Properties

	Tensile Strength (MPa)	DIN abrasion (mm)³)	Oil resistance volume change rate (%)
				Example 1	28.5	53	10.5
Example 2	27.4	52	12.8
				Example 3	30.7	55	12.3

According to the embodiment, the conveying belt provided by the invention has excellent abrasion performance and is durable in long-time transportation; the oil-resistant volume change rate is low, and the change volume of the conveying belt is small and cracks and disintegration are not easy to occur under an oily condition or when oil materials are conveyed; the tensile strength is high, and the use in harsh environment can be met.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The polyurethane cover adhesive is characterized by being prepared from the following raw materials in parts by mass: 90-110 parts of polyurethane crude rubber, 2-4 parts of a vulcanizing agent, 1-3 parts of an accelerator, 1-3 parts of an active agent, 30-40 parts of a reinforcing agent, 1-5 parts of a coupling agent, 0.5-3 parts of a release agent, 2-10 parts of a plasticizer, 0.5-8 parts of an anti-aging agent and 16-25 parts of a m-methylene system.

2. The polyurethane cap glue according to claim 1, wherein the accelerator is dibenzothiazyl disulfide and/or 2-mercaptobenzothiazole, and when dibenzothiazyl disulfide and 2-mercaptobenzothiazole are contained simultaneously, the mass ratio of dibenzothiazyl disulfide to 2-mercaptobenzothiazole is (1-2): (1-2).

3. The polyurethane cover cement according to claim 1 or 2, wherein the reinforcing agent is carbon black and/or white carbon, and when the reinforcing agent contains carbon black and white carbon, the mass ratio of the carbon black to the white carbon is (1-5): (30-35);

4. The polyurethane cap compound of claim 3, wherein the plasticizer is dioctyl phthalate, chlorinated paraffin or diphenyl phosphate;

5. A conveyor belt prepared from the polyurethane cover rubber as claimed in any one of claims 1 to 4, wherein the conveyor belt comprises the polyurethane cover rubber, the coating rubber and a framework material, and the mass ratio of the polyurethane cover rubber to the coating rubber to the framework material is (40-90): (9-30): (5-25).

6. The conveying belt according to claim 5, wherein the rubberizing comprises natural rubber, styrene-butadiene rubber and polyurethane raw rubber, and the mass ratio of the natural rubber to the styrene-butadiene rubber to the polyurethane raw rubber is (1-5): (5-9): (1-5).

7. A method of manufacturing a conveyor belt according to claim 5 or 6, comprising the steps of:

(1) banburying polyurethane cover rubber to obtain banburying cover rubber;

(2) banburying the rubberizing to obtain banburying rubberizing;

(4) and vulcanizing the semi-finished product to obtain the conveying belt.

8. The method according to claim 7, wherein the banburying in the step (1) is a first banburying and a second banburying which are sequentially performed, and the banburying pressure is 0.5 to 0.7 MPa;

9. The preparation method according to claim 7 or 8, wherein the banburying in the step (2) is carried out for 160-200 s at a banburying pressure of 0.4-0.8 MPa and at a banburying temperature of 105 ℃ or lower;

and (4) the temperature of the hot bonding in the step (3) is 50-60 ℃.

10. The method according to claim 9, wherein the pressure of the vulcanization in the step (4) is 1.7 to 1.9MPa, the time of the vulcanization is 20 to 50min, and the temperature of the vulcanization is 130 to 160 ℃.