Rubber composition, processing method thereof, and rubber product using the same

Abstract

The present invention discloses a rubber composition, production method thereof and a rubber product using the same. The rubber composition includes a rubber matrix and essential components. Based on 100 parts by weight of the rubber matrix, the rubber matrix includes a branched polyethylene with a content represented as A, in which 0<A≤100, and an EPM and an EPDM with a total content represented as B, in which 0≤B<100; and the essential components include 1.5 to 10 parts of a crosslinking agent and 40 to 200 parts of a reinforcing filler. The reinforcing filler includes carbon black and silica and can also include any one or more of calcium carbonate, talcum powder, calcined clay, magnesium silicate, and magnesium carbonate, wherein the content of the carbon black is 5 to 100 parts, and the content of the silica is 5 to 60 parts. The rubber composition is used for producing rubber product with better yield and tear strength and service performance. The rubber product include high-strength insulation compound for preparing wire and cable, waterproof coil, and high-temperature resistant conveyor belt.

Claims

1. A rubber composition, comprising a rubber matrix and essential components, wherein: based on 100 parts by weight of the rubber matrix, the rubber matrix comprises: a branched polyethylene with a content represented as A, in which 0<A≤100, and an EPM and an EPDM with a total content represented as B, in which 0≤B<100; based on 100 parts by weight of the rubber matrix, the essential components comprise: 1.5 to 10 parts of a crosslinking agent, and 40 to 200 parts of a reinforcing filler; the branched polyethylene comprises an ethylene homopolymer having a degree of branching of from 60 to 102 branches/1000 carbon atoms, a weight average molecular weight of from 268,000 to 518,000, and a Mooney viscosity ML(1+4) at 125° C. of from 42 to 102; and the reinforcing filler comprises carbon black and silica, wherein the content of the carbon black is 5 to 100 parts based on 100 parts by weight of the rubber matrix, and the content of the silica is 5 to 60 parts based on 100 parts by weight of the rubber matrix.

2. The rubber composition according to claim 1, wherein based on 100 parts by weight of the rubber matrix, the rubber matrix comprises a branched polyethylene with a content represented as A, in which 10≤A≤100, and an EPM and an EPDM with a total content represented as B, in which 0≤B≤90; and the branched polyethylene is an ethylene homopolymer having a degree of branching of from 80 to 102 branches/1000 carbon atoms.

3. The rubber composition according to claim 1, wherein the silica comprises at least one of precipitated silica and fumed silica.

4. The rubber composition according to claim 1, wherein the carbon black comprises at least one of N220, N330, N550, N660, N774, and N990.

5. The rubber composition according to claim 1, wherein the crosslinking agent comprises at least one of a peroxide crosslinking agent and sulfur, and the peroxide crosslinking agent comprises at least one of di-tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, 1,1-di-tert-butyl peroxide-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butyl peroxybenzoate, and tert-butylperoxy-2-ethylhexyl carbonate.

6. The rubber composition according to claim 1, wherein the rubber composition also comprises auxiliary components, and based on 100 parts by weight of the rubber matrix, the auxiliary components comprise 0.2 to 20 parts of an auxiliary crosslinking agent, 5 to 100 parts of a plasticizer, 1 to 3 parts of a stabilizer, 2 to 10 parts of a metal oxide, 1 to 10 parts of a surface modifier, 0 to 3 parts of a vulcanization accelerator, and 0 to 20 parts of a binder.

7. The rubber composition according to claim 6, wherein the stabilizer comprises at least one of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2-mercaptobenzimidazole, and N-4(anilinophenyl) maleimide; the auxiliary crosslinking agent comprises at least one of triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, ethyl dimethacrylate, triethylene glycol dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, N,N′-m-phenylene bismaleimide, N,N′-bis(furfurylidene)acetone, 1,2-polybutadiene, sulfur, and unsaturated carboxylic acid metal salt, wherein the unsaturated carboxylic acid metal salt comprises at least one of zinc acrylate, zinc methacrylate, magnesium methacrylate, calcium methacrylate, and aluminum methacrylate; the plasticizer comprises at least one of pine tar, engine oil, naphthenic oil, paraffin oil, coumarone, stearic acid, paraffin, and liquid polyisobutylene; the metal oxide comprises at least one of zinc oxide, magnesium oxide, and calcium oxide; the surface modifier comprises at least one of polyethylene glycol, diphenyl silandiol, triethanolamine, vinyl tris(2-methoxyethoxy)silane, γ-glycidyloxypropyl trimethoxysilane, and γ-mercaptopropyl trimethoxysilane; the vulcanization accelerator comprises at least one of 2-mercaptobenzothiazole, dibenzothiazyl disulfide, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolesulfenamide, N,N-dicyclohexyl-2-benzothiazolesulfenamide, bismaleimide, and ethylene thiourea; the binder comprises at least one of a resorcinol donor and a methylene donor.

8. A high-strength insulation compound for wire and cable comprising a rubber compound, wherein the rubber compound used for said insulation compound for high-strength wire and cable comprises said rubber composition according to claim 1.

9. A waterproof coil comprising a rubber compound, wherein the rubber compound used for said waterproof coil comprises said rubber composition according to claim 1.

10. A high-temperature resistant conveyor belt, having working surface covering rubber and non-working surface covering rubber, comprising a rubber compound, wherein, the rubber compound used for at least one of which comprises said rubber composition according to claim 1.

11. A tire comprising a rubber compound used for a sidewall of the tire and/or for the tread of the tire, wherein the rubber compound comprises said rubber composition according to claim 1.

12. The tire according to claim 11, wherein the tire is a cycle tire or an agricultural machine tire.

13. The rubber composition according to claim 1, wherein the branched polyethylene is an elastomer.

14. The rubber composition according to claim 1, wherein the reinforcing filler further comprises one or more fillers selected from the group consisting of calcium carbonate, talcum powder, calcined clay, magnesium silicate, and magnesium carbonate.

Description

DETAILED DESCRIPTION

(1) The present invention is further described through examples below, but such examples are not intended to limit the scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention shall also fall within the protection scope of the present invention.

(2) In order to more clearly describe the examples of the present invention, the materials involved in the present invention are defined below.

(3) The crosslinking system includes a crosslinking agent and can also include at least one of an auxiliary crosslinking agent and a vulcanization accelerator.

(4) The Mooney viscosity ML(1+4) at 125° C. of the used EPM is preferably 20 to 50 and further preferably 40 to 50, and the ethylene content is preferably 45 to 60%.

(5) The Mooney viscosity ML(1+4) at 125° C. of the used EPDM is preferably 20 to 100 and further preferably 40 to 80, the ethylene content is preferably 55 to 75%, the third monomer is 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene or dicyclopentadiene, and the content of the third monomer is 1% to 7%.

(6) The used branched polyethylene can be obtained by catalyzing ethylene homopolymerization by means of an (α-diimine) nickel catalyst under the action of a co-catalyst. The structure and synthetic method of the used (α-diimine) nickel catalyst and the method for preparing the branched polyethylene by means of the (α-diimine) nickel catalyst are disclosed in the prior art, as described in, but are not limited to the following literatures: CN102827312A, CN101812145A, CN101531725A, CN104926962A, U.S. Pat. Nos. 6,103,658, and 6,660,677.

(7) The branched polyethylene involved in the examples has the following characteristics: the degree of branching is 60 to 130 branches/1000 carbon atoms, the weight average molecular weight is 66,000 to 518,000, and the Mooney viscosity ML(1+4) at 125° C. is 6 to 102.

(8) The rubber composition provided by the present invention includes a rubber matrix and essential components. The rubber matrix includes a branched polyethylene with a content represented as A, in which 0<A≤100, and an EPM and an EPDM with a total content represented as B, in which 0≤B<100. The essential components include 1.5 to 10 parts of a crosslinking agent and 40 to 200 parts of a reinforcing filler. The reinforcing filler includes two or more of carbon black, silica, calcium carbonate, talcum powder, calcined clay, magnesium silicate, and magnesium carbonate, wherein when the reinforcing filler includes carbon black or silica, the content of the carbon black is 5 to 100 parts, and the content of the silica is 5 to 60 parts. The silica in the reinforcing filler includes at least one of precipitated silica and fumed silica, and the carbon black in the reinforcing filler includes at least one of N220, N330, N550, N660, N774, and N990. The crosslinking agent includes at least one of a peroxide crosslinking agent and sulfur, wherein the peroxide crosslinking agent includes at least one of di-tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, 1,1-di-tert-butyl peroxide-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butyl peroxybenzoate, and tert-butylperoxy-2-ethylhexyl carbonate.

(9) The silica used in the examples of the present invention is fumed silica or precipitated silica. For an application occasion with lower requirements for transparency and electrical insulating property, preferably, the precipitated silica is used, and further preferably, high-dispersibility precipitated silica is used. Unless otherwise specified, the grade of the common precipitated silica used in the examples is Solvay Rhodia zeosil1142, and the grade of the high-dispersibility silica used in the examples is Solvay Rhodia zeosil165N.

(10) The rubber composition provided by the present invention can also include auxiliary components. The auxiliary components include 0.2 to 20 parts of an auxiliary crosslinking agent, 5 to 100 parts of a plasticizer, 1 to 3 parts of a stabilizer, 2 to 10 parts of a metal oxide, 1 to 10 parts of a surface modifier, 0 to 3 parts of a vulcanization accelerator, and 0 to 20 parts of a binder, wherein the stabilizer includes at least one of 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (AW), and 2-mercaptobenzimidazole (MB).

(11) The auxiliary crosslinking agent includes at least one of triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, ethyl dimethacrylate, triethylene glycol dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, N,N′-m-phenylene bismaleimide, N,N′-bis(furfurylidene)acetone, 1,2-polybutadiene, sulfur, and a metal salt of unsaturated carboxylic acid.

(12) The metal salt of unsaturated carboxylic acid includes at least one of zinc acrylate, zinc methacrylate, magnesium methacrylate, calcium methacrylate, and aluminum methacrylate. The plasticizer includes at least one of pine tar, engine oil, naphthenic oil, paraffin oil, coumarone, RX-80, stearic acid, and paraffin.

(13) The metal oxide includes at least one of zinc oxide, magnesium oxide, and calcium oxide.

(14) The surface modifier includes at least one of polyethylene glycol, diphenyl silandiol, triethanolamine, vinyl tris(2-methoxyethoxy)silane (A-172), γ-glycidyloxypropyl trimethoxysilane (A-187), and γ-mercaptopropyl trimethoxysilane (A-189) with a molecular weight of 2000 or 3400 or 4000.

(15) The vulcanization accelerator includes at least one of 2-mercaptobenzothiazole, dibenzothiazyl disulfide, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolesulfenamide, N,N-dicyclohexyl-2-benzothiazolesulfenamide, bismaleimide, and ethylene thiourea.

(16) The binder includes at least one of a resorcinol donor, a methylene donor, and a triazine binder.

(17) The degree of branching of the branched polyethylene in the rubber composition is measured by means of nuclear magnetic hydrogen spectroscopy, and the molar percentages of various branches are measured by means of nuclear magnetic carbon spectroscopy. Specific details are as follows:

(18) TABLE-US-00001 Weight average Mooney Branched Degree Hexyl molecular Molecular viscosity polyethylene of or weight/ weight ML (1 + 4) No. branching Methyl/% Ethyl/% Propyl/% Butyl/% Pentyl/% higher/% 10,000 distribution 125° C. PER-1 130 46.8 18.3 8.3 6.7 5.2 14.7 6.6 2.2 6 PER-2 116 51.2 17.6 8.2 5.8 5.1 12.1 20.1 2.1 23 PER-3 105 54.0 13.7 6.4 5.3 5.1 15.5 26.8 2.1 42 PER-4 102 56.2 12.9 6.2 5.2 4.9 14.6 27.9 2.1 52 PER-5 99 59.6 11.6 5.8 4.9 5.1 13.0 28.3 1.8 63 PER-6 90 62.1 9.4 5.4 4.6 4.5 14.0 32.1 2.1 77 PER-7 82 64.2 8.7 5.3 4.2 3.9 13.7 35.6 1.7 80 PER-8 70 66.5 7.2 4.6 3.2 3.2 15.3 43.6 2.1 93 PER-9 60 68.1 7.1 4.2 2.7 2.8 15.1 51.8 2.2 102 PER-10 87 61.8 10.3 5.4 4.6 4.9 12.0 40.1 1.8 101 PER-11 94 60.5 10.8 5.7 4.7 4.9 13.3 37.8 2.0 85 PER-12 102 56.8 12.7 6.1 5.2 5.1 13.9 34.8 1.9 66

(19) Rubber Performance Test Method:

(20) 1. Hardness test: the test is performed by using a hardness tester in accordance with the national standard GB/T 531.1-2008, wherein the test temperature is room temperature.

(21) 2. Tensile strength and elongation at break performance test: the test is performed by using an electronic tensile tester in accordance with the national standard GB/T528-2009, wherein the tensile speed is 500 mm/min, the test temperature is 23±2° C., and the sample is a type 2 dumbbell-shaped sample.

(22) 3. Tear strength test: the test is performed by using an electronic tensile tester in accordance with the national standard GB/T529-2008, wherein the tensile speed is 500 mm/min, the test temperature is 23±2° C., and the sample is a right-angle sample.

(23) 4. Volume resistivity test: the test is performed by using a megger in accordance with the national standard GB/T1692-2008.

(24) 5. Mooney viscosity test: the test is performed by using a Mooney viscosity tester in accordance with the national standard GB/T1232.1-2000, wherein the test temperature is 125° C., the preheating time is 1 min, and the test time is 4 min.

(25) 6. Hot air accelerated aging test: the test is performed in a heat aging test box in accordance with the national standard GB/T3512-2001, wherein the test condition is 150° C.*72 h.

(26) 7. Test of top optimum cure time Tc90: the test is performed in a rotorless vulcanizer in accordance with the national standard GB/T16584-1996, wherein the test temperature is 160° C.

(27) The vulcanization conditions of the following examples 1 to 10 and comparative examples 1 to 2 are unified as follows: the temperature is 160° C., the pressure is 16 MPa, and the time is Tc90+2 min.

(28) In order to more clearly illustrate the performance of the rubber composition, the present invention is further described below in conjunction with specific examples.

Example 1

(29) Branched polyethylene No. PER-5 was used.

(30) The processing steps of the rubber composition were as follows:

(31) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 50 parts of EPDM and 50 parts of branched polyethylene were added, and pre-pressing and mixing were performed for 90 s; 40 parts of carbon black N550 and 10 parts of silica were added, and mixing was performed for 3 min; then, 3 parts of a crosslinking agent dicumyl peroxide (DCP) was added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(32) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 2

(33) Branched polyethylene No. PER-5 was used.

(34) The processing steps of the rubber composition were as follows:

(35) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressing and mixing were performed for 90 s; 40 parts of carbon black N550 and 10 parts of silica were added, and mixing was performed for 3 min; then, 3 parts of a crosslinking agent dicumyl peroxide (DCP) was added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(36) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Comparative Example 1

(37) The processing steps were as follows:

(38) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of EPDM was added, and pre-pressing and mixing were performed for 90 s; 40 parts of carbon black N550 and 10 parts of silica were added, and mixing was performed for 3 min; then, 3 parts of a crosslinking agent dicumyl peroxide (DCP) was added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(39) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 3

(40) Branched polyethylene No. PER-9 was used.

(41) The processing steps of the rubber composition were as follows:

(42) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 90 parts of EPDM and 10 parts of branched polyethylene were added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 80 parts of carbon black N550, 20 parts of silica, 20 parts of calcined clay, 20 parts of vaseline, and 30 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 6 parts of a crosslinking agent dicumyl peroxide (DCP), 2 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 0.3 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(43) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 4

(44) Branched polyethylene No. PER-8 was used.

(45) The processing steps of the rubber composition were as follows:

(46) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 20 parts of EPM, 50 parts of EPDM, and 30 parts of branched polyethylene were added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polyethylene glycol PEG4000, 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), and 1 part of vinyl tris(2-methoxyethoxy)silane (A-172) were added, and mixing was performed for 2 min; then, 80 parts of carbon black N550, 20 parts of silica, 20 parts of calcined clay, 15 parts of vaseline, and 30 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 6 parts of a crosslinking agent dicumyl peroxide (DCP), 2 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 0.2 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(47) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 5

(48) Branched polyethylene No. PER-6 was used.

(49) The processing steps of the rubber composition were as follows:

(50) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 30 parts of EPDM and 70 parts of branched polyethylene were added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 80 parts of carbon black N550, 20 parts of silica, 20 parts of calcined clay, 15 parts of vaseline, and 30 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 6 parts of a crosslinking agent dicumyl peroxide (DCP), 2 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 0.2 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(51) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 6

(52) Branched polyethylene No. PER-5 was used.

(53) The processing steps of the rubber composition were as follows:

(54) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 80 parts of carbon black N550, 20 parts of silica, 20 parts of calcined clay, 15 parts of vaseline, and 30 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 6 parts of a crosslinking agent dicumyl peroxide (DCP), 2 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 0.2 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(55) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Comparative Example 2

(56) The processing steps were as follows:

(57) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of EPDM was added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 80 parts of carbon black N550, 20 parts of silica, 20 parts of calcined clay, 15 parts of vaseline, and 30 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 6 parts of a crosslinking agent dicumyl peroxide (DCP), 2 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 0.2 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(58) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

(59) Performance Test Data Analysis

(60) TABLE-US-00002 Comparative Comparative Test Item Example 1 Example 2 Example 1 Example 3 Example 4 Example 5 Example 6 Example 2 Hardness 64 64 63 57 62 60 59 55 Tensile 18.7 20.5 16.3 12.1 14.2 15.9 17.2 11.8 strength/ MPa Elongation 452 481 429 403 389 409 453 418 at break/% Tear 34.7 39.2 31.6 31.2 33.8 35.9 38.6 29.2 strength/ (N/mm) After aging (150° C. * 72 h) Hardness 68 67 67 66 70 68 66 65 Retention 83 84 81 78 81 82 79 76 rate of tensile strength/% Retention 85 82 84 61 63 72 77 58 rate of elongation at break/%

(61) Performance Test Data Analysis:

(62) By means of comparison of the examples 1 to 2 and the comparative example 1 and comparison of the examples 3 to 6 and the comparative example 2, it can be found that as the proportion of the branched polyethylene replacing the ethylene propylene rubber increased, the tensile strength and tear strength of the obtained vulcanized rubber were obviously enhanced, thereby indicating that better mechanical properties can be obtained by using the rubber composition containing the branched polyethylene.

Example 7

(63) Branched polyethylene No. PER-5 was used.

(64) The processing steps of the rubber composition were as follows:

(65) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressing and mixing were performed for 90 s; then, 10 parts of zinc oxide, 2 parts of stearic acid, 3 parts of polyethylene glycol PEG4000, 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), and 2 parts of vinyl tris(2-methoxyethoxy)silane (A-172) were added, and mixing was performed for 2 min; then, 100 parts of carbon black N550, 30 parts of silica, 30 parts of calcined clay, 40 parts of talcum powder, 20 parts of vaseline, and 60 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 10 parts of a crosslinking agent dicumyl peroxide (DCP), 2 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 8 parts of an auxiliary crosslinking agent 1,2-polybutadiene were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(66) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 8

(67) Branched polyethylene No. PER-4 was used.

(68) The processing steps of the rubber composition were as follows:

(69) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polyethylene glycol PEG4000, 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), and 2 parts of vinyl tris(2-methoxyethoxy)silane (A-172) were added, and mixing was performed for 2 min; then, 20 parts of carbon black N550, 60 parts of silica, 40 parts of calcined clay, 15 parts of vaseline, and 30 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 8 parts of a crosslinking agent dicumyl peroxide (DCP), 1 part of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 6 parts of an auxiliary crosslinking agent 1,2-polybutadiene were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(70) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 9

(71) Branched polyethylene Nos. PER-2 and PER-6 were used.

(72) The processing steps of the rubber composition were as follows:

(73) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 70 parts of PER-6 and 30 parts of PER-2 were added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 2 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 35 parts of carbon black N550, 5 parts of silica, and 10 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 1 part of a crosslinking agent dicumyl peroxide (DCP), 0.3 part of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), 0.5 part of a crosslinking agent sulfur, 1 part of N-cyclohexyl-2-benzothiazole sulfenamide (CZ), and 0.8 part of tetramethylthiuram disulfide (TMTD) were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(74) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 10

(75) Branched polyethylene Nos. PER-1 and PER-7 were used.

(76) The processing steps of the rubber composition were as follows:

(77) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 80 parts of PER-7 and 20 parts of PER-1 were added, and pre-pressing and mixing were performed for 90 s; then, 10 parts of zinc oxide, 2 parts of stearic acid, 2 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 60 parts of carbon black N330, 20 parts of silica, and 20 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 4 parts of a crosslinking agent bis(1-(tert-butylperoxy)-1-methylethyl)-benzene (BIPB), 1.5 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 15 parts of zinc methacrylate were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(78) (2) vulcanization was performed, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

(79) Performance test data was as shown in the following table:

(80) TABLE-US-00003 Test item Example 7 Example 8 Example 9 Example 10 Hardness 67 66 58 71 Tensile strength/MPa 15.4 13.2 18.2 20.2 Elongation at break % 368 539 522 489 Tear strength N/mm 37.2 42.1 35.8 49.7 After aging (150° C. * 72 h) Hardness 74 75 62 79 Retention rate of 75 83 81 89 tensile strength/% Retention rate of 72 79 78 87 elongation at break/%

(81) A specific example of the present invention also provides application of the rubber composition in preparation of rubber products. The rubber products include high-strength insulation compound for wire and cable, waterproof coil, and high-temperature resistant conveyor belts. The specific implementation of the application was as follows:

Example 11

(82) The present example is a high-strength insulation compound for wire and cable, which used the branched polyethylene No. PER-3, and the processing steps of the insulation compound were as follows:

(83) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressing and mixing were performed for 90 s; then, 10 parts of zinc oxide, 1 part of stearic acid, 2 parts of polyethylene glycol PEG4000, and 2 parts of vinyl tris(2-methoxyethoxy)silane (A-172) were added, and mixing was performed for 2 min; then, 5 parts of carbon black N330, 45 parts of silica, 2 parts of vaseline, and 15 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 4 parts of a crosslinking agent dicumyl peroxide (DCP) and 0.3 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill, the roller spacing was increased to obtain a sheet of which the thickness was about 2.5 mm, the sheet was unloaded, and the sheet was allowed to stand for 20 h;

(84) (2) granulation: the rubber mix was put into an extruding machine so as to be extruded, sheared, and granulated and then was packaged.

(85) Vulcanization and performance test and vulcanization process: the steam vulcanization was performed at 155° C. for 40 min, and then, the vulcanized product was dipped in water.

(86) Performance test: the hardness was 68, the tensile strength was 19.1 MPa, the elongation at break was 622%, and the volume resistivity was 3.8×10.sup.15Ω.Math.cm. After hot air aging at 150° C. for 72 h: the hardness was 74, the retention rate of the tensile strength was 75%, and the retention rate of the elongation at break was 72%.

Example 12

(87) The present example is a waterproof coil and a production process thereof was as follows:

(88) (1) mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene PER-5 was added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 80 parts of carbon black N550, 20 parts of silica, 20 parts of calcined clay, 15 parts of vaseline, and 30 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 6 parts of a crosslinking agent dicumyl peroxide (DCP), 2 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 0.2 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; a blocky rubber mix was conveyed into an open mill so as to be mixed, the roller temperature was controlled to be between 85° C. and 95° C., the roller spacing was controlled to be less than 1 mm, the rubber was plasticated at least four times until the surface of the rubber mix was smooth, uniform and glossy, then, the rubber mix was further mixed and plasticated at least four times, the roller spacing was adjusted to be not greater than 8 mm, mixing was performed three times to obtain a uniformly-mixed rough rubber sheet of which the thickness was lower than 8 mm, the sheet was cooled to be lower than 50° C., and then, the sheet was discharged and stacked;

(89) (2) hot milling: hot milling was performed on the uniformly-mixed rough rubber sheet on an open mill, the roller temperature was controlled to be between 85° C. and 95° C., the roller spacing was controlled to be less than 6 mm until the rubber material sheet was smooth and uniform, and then, the sheet was preliminarily coiled;

(90) (3) calendering: the rubber sheet which was preliminarily coiled by means of hot milling was put on a calender, and the roller spacing was adjusted according to the thickness requirement of a finished product to perform calendering so as to obtain a semi-finished coil meeting the thickness specification requirement of the finished product;

(91) (4) coiling: an isolation liner layer was sandwiched according to the specification length requirement of the finished coil, and the semi-finished coil was tidied into a coil;

(92) (5) vulcanization: the coil which was tidied into a coil was put into a nitrogen-filled vulcanization kettle so as to be vulcanized, the temperature of the vulcanization kettle was controlled to be between 155° C. and 165° C., the pressure of the vulcanization kettle was controlled to be 20 MPa and 25 MPa, and vulcanization was performed for 25 to 30 min;

(93) (6) recoiling: the vulcanized coil was opened again, the isolation liner layer was taken out, and then, the coil was recoiled and packaged to obtain a product.

Example 13

(94) The present example is a high-temperature resistant conveyor belt including working surface covering rubber, non-working surface covering rubber, and a belt core tensile canvas arranged between the working surface covering rubber and the non-working surface covering rubber, and the components and proportions of the working surface covering rubber were metered in parts:

(95) (1) Rubber Mixing Process:

(96) primary mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 80 parts of PER-7 and 20 parts of PER-1 were added, and pre-pressing and mixing were performed for 90 s; then, 10 parts of zinc oxide, 2 parts of stearic acid, 2 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 60 parts of carbon black N330, 20 parts of silica, 2.5 parts of resorcinol (RS), and 20 parts of paraffin oil SUNPAR2280 were added, mixing was performed for 3 min, and then, the rubber was discharged; secondary mixing: the temperature of the internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, then, 2 parts of a methylene donor RH was added, and mixing was performed for 2 min; then, 4 parts of a crosslinking agent bis(1-(tert-butylperoxy)-1-methylethyl)-benzene (BIPB), 1.5 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 15 parts of zinc methacrylate were added, mixing was performed for 2 min, and then, the rubber was discharged;

(97) (2) Calendering Process:

(98) the rubber mix was put into a screw extruder so as to be subjected to hot milling, then, the rubber mix after hot milling was conveyed into a calender so as to be calendered, and then, the sheet was discharged for later use; the thickness of the rubber sheet was controlled to be 4.5 to 12 mm in the processes of calendering and discharging the sheet; after the sheet was discharged, the temperature of the sheet was kept for later use;

(99) (3) Forming Process:

(100) the rubber sheet and a preformed rubberized canvas belt blank were closely attached together on a forming machine to form a belt blank of a high-temperature resistant conveyor belt, then, the belt blank was coiled, and after 4 h, the belt blank was vulcanized;

(101) (4) Vulcanization Process:

(102) the formed belt blank of the conveyor belt was put into a press vulcanizer so as to be vulcanized in sections, wherein for each plate, the vulcanization time was 25 min, the vulcanization pressure was 3 MPa, and the vulcanization temperature was 160° C.

Example 14

(103) The present example is a cycle tire, and the processing steps of the sidewall rubber of the cycle tire were as follows:

(104) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene PER-5 was added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 2 parts of polyethylene glycol PEG4000, and 2 parts of vinyl tris(2-methoxyethoxy)silane (A-172) were added, and mixing was performed for 2 min; then, 40 parts of carbon black N330, 20 parts of high-dispersibility silica, and 10 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 4 parts of a crosslinking agent dicumyl peroxide (DCP), 1.5 parts of an auxiliary crosslinking agent N,N′-m-phenylene bismaleimide (HVA-2), and 0.3 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; open milling was performed on the rubber mix on an open mill, then, the sheet was unloaded, the sheet was allowed to stand, and then, the sheet was detected;

(105) (2) extrusion forming: extrusion forming was performed on the qualified rubber mix by means of an extruding machine to obtain a rubber part in a sidewall shape for later use.

Example 15

(106) The present example is a cycle tire, and the processing steps of the sidewall rubber of the cycle tire were as follows:

(107) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene PER-12 was added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 2 parts of polyethylene glycol PEG4000, and 2 parts of vinyl tris(2-methoxyethoxy)silane (A-172) were added, and mixing was performed for 2 min; then, 40 parts of carbon black N330, 20 parts of high-dispersibility silica, and 10 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 4 parts of a crosslinking agent dicumyl peroxide (DCP), 1.5 parts of an auxiliary crosslinking agent N,N′-m-phenylene bismaleimide (HVA-2), and 0.3 part of an auxiliary crosslinking agent sulfur were added, mixing was performed for 2 min, and then, the rubber was discharged; open milling was performed on the rubber mix on an open mill, then, the sheet was unloaded, the sheet was allowed to stand, and then, the sheet was detected;

(108) (2) extrusion forming: extrusion forming was performed on the qualified rubber mix by means of an extruding machine to obtain a rubber part in a sidewall shape for later use.

Example 16

(109) The present example is a cycle tire, and the processing steps of the tread rubber of the cycle tire were as follows:

(110) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 80 parts of PER-7 and 20 parts of PER-1 were added, and pre-pressing and mixing were performed for 90 s; then, 10 parts of zinc oxide, 2 parts of stearic acid, 2 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD) were added, and mixing was performed for 2 min; then, 60 parts of carbon black N330, 20 parts of silica, and 15 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 4 parts of a crosslinking agent bis(1-(tert-butylperoxy)-1-methylethyl)-benzene (BIPB), 1.5 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 15 parts of zinc methacrylate were added, mixing was performed for 2 min, and then, the rubber was discharged; open milling was performed on the rubber mix on an open mill, then, the sheet was unloaded, the sheet was allowed to stand, and then, the sheet was detected;

(111) (2) the qualified rubber mix was calendered to obtain an appropriate thickness, and then, the rubber mix with the appropriate thickness was cut into strips for later use;

(112) (3) tread extrusion: a tread semi-finished product was extruded by an extruding machine according to a cold feeding extrusion process.

Example 17

(113) The present example is a cycle tire, and the processing steps of the tread rubber of the cycle tire were as follows:

(114) (1) rubber mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 70 parts of PER-11 and 30 parts of PER-3 were added, and pre-pressing and mixing were performed for 90 s; then, 10 parts of zinc oxide, 2 parts of stearic acid, 2 parts of coumarone resin, 2 parts of modified alkyl phenolic resin TKM-K, 2 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent RD were added, and mixing was performed for 2 min; then, 60 parts of carbon black N330, 20 parts of silica, and 20 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 4 parts of a crosslinking agent bis(1-(tert-butylperoxy)-1-methylethyl)-benzene (BIPB), 1.5 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 3 parts of zinc methacrylate were added, mixing was performed for 2 min, and then, the rubber was discharged; open milling was performed on the rubber mix on an open mill, then, the sheet was unloaded, the sheet was allowed to stand, and then, the sheet was detected;

(115) (2) the qualified rubber mix was calendered to obtain an appropriate thickness, and then, the rubber mix with the appropriate thickness was cut into strips for later use;

(116) (3) tread extrusion: a tread semi-finished product was extruded by an extruding machine according to a cold feeding extrusion process.

Example 18

(117) The present example is a high-temperature resistant conveyor belt including working surface covering rubber, non-working surface covering rubber, and a belt core tensile canvas arranged between the two, and the composition and mixing process of the working surface covering rubber were as follows:

(118) primary mixing: the temperature of an internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, 100 parts of PER-12 was added, and pre-pressing and mixing were performed for 90 s; then, 10 parts of zinc oxide, 2 parts of stearic acid, 2 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent RD were added, and mixing was performed for 2 min; then, 60 parts of carbon black N330, 20 parts of silica, 5 parts of a triazine binder AIR-1, 1 part of resorcinol (RS), and 20 parts of paraffin oil SUNPAR2280 were added, mixing was performed for 3 min, and then, the rubber was discharged; secondary mixing: the temperature of the internal mixer was set to be 90° C. and the rotor speed was set to be 50 r/min, then, 2 parts of a methylene donor RH was added, and mixing was performed for 2 min; then, 4 parts of a crosslinking agent bis(1-(tert-butylperoxy)-1-methylethyl)-benzene (BIPB), 1.5 parts of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), and 15 parts of zinc methacrylate were added, mixing was performed for 2 min, and then, the rubber was discharged.

(119) The other production processes were the same as those in the example 13.

Example 19

(120) The present example is a rubber for a rubber metal damping part, and the components and mixing process of the rubber were as follows:

(121) the temperature of an internal mixer was set to be 100° C. and the rotor speed was set to be 50 r/min, 40 parts of EPDM (keltan 9565Q) and 60 parts of PER-10 were added, and pre-pressing and mixing were performed for 90 s; then, 5 parts of zinc oxide, 1 part of stearic acid, 4 parts of a binder RS, 2 parts of polyethylene glycol PEG4000, and 1 part of an anti-aging agent RD were added, and mixing was performed for 2 min; then, 60 parts of carbon black N330, 20 parts of silica, and 20 parts of paraffin oil SUNPAR2280 were added, and mixing was performed for 3 min; then, 4 parts of a binder RA-65 was added, and mixing was performed for 1 min; then, 4 parts of a crosslinking agent bis(1-(tert-butylperoxy)-1-methylethyl)-benzene (BIPB), 1 part of an auxiliary crosslinking agent triallyl isocyanurate (TAIC), 0.5 part of sulfur, and 3 parts of zinc methacrylate were added, mixing was performed for 2 min, and then, the rubber was discharged; open milling was performed on the rubber mix on an open mill, then, the sheet was unloaded, and the sheet was allowed to stand for later use.