RUBBER COMPOSITE, PROCESSING METHOD, HIGH-STRENGTH PRODUCT APPLYING COMPOSITE, AND MANUFACTURING METHOD

Abstract

The present invention discloses a rubber composition. The rubber composition includes a rubber matrix and a crosslinking system. The rubber matrix includes, in parts by weight, the following components: a branched polyethylene with a content represented as A, in which 0<A100, an EPM with a content represented as B, in which 0B<100, and an EPDM with a content represented as C, in which 0C<100. Based on 100 parts by weight of said rubber matrix, the content of the crosslinking system is represented as D: 1D15 parts. The crosslinking system includes at least one of a crosslinking agent and an auxiliary crosslinking agent. The branched polyethylene has a degree of branching of not less than 50 branches/1000 carbon atoms, a weight average molecular weight of not less than 50,000, and a Mooney viscosity ML(1+4) at 125 C. of not less than 2. The rubber composition provided by the present invention can effectively solve the problems of low crosslinking efficiency and mechanical strength in the prior art, and simultaneously has good electrical insulation properties and mechanical strength.

Claims

1. A rubber composition, comprising a rubber matrix and a crosslinking system, wherein, said rubber matrix comprises, based on 100 parts by weight of said rubber matrix, the following components: a branched polyethylene with a content represented as A, in which 0<A100, an EPM with a content represented as B, in which 0C<100, and an EPDM with a content represented as C, in which 0C<100; based on 100 parts by weight of said rubber matrix, the content of said crosslinking system is represented as D: 1D15 parts; said crosslinking system comprises at least one of a crosslinking agent and an auxiliary crosslinking agent; and said branched polyethylene comprises an ethylene homopolymer having a branching degree of not less than 50 branches/1000 carbon atoms, a weight average molecular weight of not less than 50,000, and a Mooney viscosity ML(1+4) at 125 C. of not less than 2.

2. The rubber composition according to claim 1, wherein, in 100 parts by weight of said rubber matrix, said branched polyethylene is represented as A, in which 10A100, said EPM is represented as B, in which 0B90, and said EPDM is represented as C, in which 0C90; and said branched polyethylene is an ethylene homopolymer having a branching degree of 60 to 130 branches/1000 carbon atoms, a weight average molecular weight of 66,000 to 518,000, and a Mooney viscosity ML(1+4) at 125 C. of 6 to 102.

3. The rubber composition according to claim 1, wherein, said crosslinking agent comprises at least one of sulfur and a peroxide crosslinking agent, and said 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.

4. The rubber composition according to claim 1, wherein, said auxiliary crosslinking agent comprises at least one of triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, ethyl dimethacrylate, triethylene glycol dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, N,N-m-phenylene bismaleimide, N,N-bis(furfurylidene)acetone, 1,2-polybutadiene, and sulfur.

5. The rubber composition according to claim 1, wherein, based on 100 parts by weight of said rubber matrix, said crosslinking system further comprises 0 to 3 parts of a vulcanization accelerator, and said 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.

6. The rubber composition according to claim 1, wherein, said rubber composition further comprises auxiliary components, and which auxiliary components comprise, based on 100 parts by weight of the rubber matrix, the following components in parts by weight: 2 to 10 parts of a metal oxide, 5 to 50 parts of a plasticizer, 0 to 10 parts of a coloring agent, 30 to 200 parts of an inorganic filler, 1 to 3 parts of a stabilizer, and 1 to 2 parts of a coupling agent.

7. The rubber composition according to claim 6, wherein, said metal oxide comprises at least one of zinc oxide, magnesium oxide, calcium oxide, lead monoxide, and lead tetraoxide; said plasticizer comprises at least one of pine tar, engine oil, naphthenic oil, paraffin oil, coumarone, RX-80, stearic acid, and paraffin; said coloring agent comprises at least one of carbon black, titanium pigment, pigment blue, and pigment green; said inorganic filler comprises at least one of calcium carbonate, talcum powder, calcined clay, magnesium silicate, and magnesium carbonate; said stabilizer comprises 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); and said coupling agent comprises at least one of vinyl tris(2-methoxyethoxy)silane (A-172), -glycidyloxypropyl trimethoxysilane (A-187), and -mercaptopropyl trimethoxysilane (A-189).

8. A wire, comprising a conductor and an insulating layer, wherein, the rubber compound used for said insulating layer comprises said rubber composition according to claim 1.

9. (canceled)

10. A cable, comprising a conductor, an insulating layer, and a sheath layer, wherein, the rubber compound used for at least one of said insulating layer and said sheath layer comprises the rubber composition according to claim 1.

11.-22. (canceled)

23. A high strength rubber product, wherein, the rubber compound used for said high strength rubber product comprises said rubber composition according to claim 1.

24. The high strength rubber product according to claim 23, wherein, said high strength rubber product is a glove, wherein, the rubber compound used for said glove comprises said rubber composition.

25. The high strength rubber product according to claim 23, wherein, said high strength rubber product is a condom, wherein, the rubber compound used for said condom comprises said rubber composition.

26. The high strength rubber product according to claim 25, wherein, said crosslinking system in said rubber composition comprises a radiation-sensitized auxiliary crosslinking agent.

27. The high strength rubber product according to claim 23, wherein, said high strength rubber product is a rubber plug, wherein, the rubber compound used for said rubber plug comprises said rubber composition.

28. The high strength rubber product according to claim 23, wherein, said high strength rubber product is a catheter, wherein, the rubber compound used for said catheter comprises said rubber composition, and said catheter is a medical catheter or a food catheter.

Description

DETAILED DESCRIPTION

[0103] The present invention is further described through examples, 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.

[0104] For the EPM used, the Mooney viscosity ML(1+4) at 125 C. is preferably 20 to 50, and the ethylene content is preferably 45% to 60%.

[0105] For the EPDM used, the Mooney viscosity ML(1+4) at 125 C. is preferably 20 to 100, 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%.

[0106] The branched polyethylene used can be obtained by catalyzing ethylene homopolymerization by means of an (-diimine) nickel catalyst under the action of a co-catalyst. The structure and synthetic method of the used (-diimine) nickel catalyst and the method for preparing the branched polyethylene by means of the (-diimine) nickel catalyst are disclosed in the prior art, and can use but are not limited to the following literatures: CN102827312A, CN101812145A, CN101531725A, CN104926962A, U.S. Pat. Nos. 6,103,658, and 6,660,677.

[0107] 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. The degree of branching is measured by nuclear magnetic hydrogen spectroscopy, and the molar percentages of various branches are measured by nuclear magnetic carbon spectroscopy.

[0108] The specific parameters of the branched polyethylene used in the following specific examples are as shown in table 1.

TABLE-US-00001 TABLE 1 Specific parameters of branched polyethylene Hexyl Weight Branched Degree or average Molecular Mooney poly- of higher molecular weight viscosity ethylene branch- Methyl/ Ethyl/ Propyl/ Butyl/ Pentyl/ branch/ weight/ distribu- ML(1 + 4) No. ing % % % % % % 10,000 tion 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

[0109] Unless otherwise specified, rubber performance test methods in specific examples and related experiments are as follows:

[0110] 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.

[0111] 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 232 C., and the sample is a type 2 dumbbell sample.

[0112] 3. 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.

[0113] 4. 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.

[0114] 5. Volume resistivity test: the test is performed by using a megger in accordance with the national standard GB/T1692-2008.

[0115] 6. 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.

Example 1

[0116] Branched polyethylene No. PER-9 was used.

[0117] The processing method was as follows:

[0118] (1) rubber mixing: the temperature of an internal mixer was set to be 100 C. and the rotor speed was set to be 50 r/min, 90 parts of EPM and 10 parts of branched polyethylene were added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 100 parts of talcum powder and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent dicumyl peroxide (DCP) and 1 part of an auxiliary crosslinking agent triallyl isocyanurate (TAIC) were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0119] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 2

[0120] Branched polyethylene No. PER-2 was used.

[0121] The processing method was as follows:

[0122] (1) rubber mixing: the temperature of an internal mixer was set to be 60 C. and the rotor speed was set to be 50 r/min, 70 parts of EPM and 30 parts of branched polyethylene were added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 100 parts of talcum powder and 10 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent DCP and 0.3 part of sulfur were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 40 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0123] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 3

[0124] Branched polyethylene No. PER-4 was used.

[0125] The processing method was as follows:

[0126] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 50 parts of EPM and 50 parts of branched polyethylene were added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 100 parts of talcum powder and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent DCP and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0127] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 4

[0128] Branched polyethylene No. PER-3 was used.

[0129] The processing method was as follows:

[0130] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 100 parts of talcum powder and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent DCP and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0131] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 5

[0132] Branched polyethylene No. PER-9 was used.

[0133] The processing method was as follows:

[0134] (1) rubber mixing: the temperature of an internal mixer was set to be 100 C. and the rotor speed was set to be 50 r/min, 85 parts of EPDM and 15 parts of branched polyethylene were added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 5 part of lead tetraoxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 120 parts of talcum powder, 5 parts of a coloring agent carbon black N550, and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 1.5 parts of sulfur, 1.5 parts of an accelerator N-cyclohexyl-2-benzothiazolesulfenamide, and 0.4 part of an accelerator tetramethylthiuram disulfide were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0135] (2) vulcanization: vulcanization was performed for 15 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 6

[0136] Branched polyethylene No. PER-8 was used.

[0137] The processing method was as follows:

[0138] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 30 parts of EPM, 50 parts of EPDM, and 20 parts of branched polyethylene were added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 120 parts of talcum powder, 5 parts of a coloring agent carbon black N550, and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent DCP and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0139] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 7

[0140] Branched polyethylene No. PER-5 was used.

[0141] The processing method was as follows:

[0142] (1) rubber mixing: the temperature of an internal mixer was set to be 80 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-pressed and mixed for 90 s; 10 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 120 parts of talcum powder, 5 parts of a coloring agent carbon black N550, and 40 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 1.5 parts of a crosslinking agent DCP and 0.3 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0143] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 8

[0144] Branched polyethylene No. PER-6 was used.

[0145] The processing method was as follows:

[0146] (1) rubber mixing: the temperature of an internal mixer was set to be 80 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-pressed and mixed for 90 s; 10 parts of zinc oxide, 2 parts of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 120 parts of talcum powder, 80 parts of calcined clay, 1 part of vinyl tris(2-methoxyethoxy)silane, 5 parts of a coloring agent carbon black N550, and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 5 parts of a crosslinking agent DCP, 2 parts of an auxiliary crosslinking agent TAIC, and 8 parts of an auxiliary crosslinking agent 1,2-polybutadiene were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0147] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Example 9

[0148] Branched polyethylene No. PER-5 was used.

[0149] The processing method was as follows:

[0150] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 120 parts of calcined clay, 2 parts of vinyl tris(2-methoxyethoxy)silane, 5 parts of a coloring agent carbon black N550, and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent DCP and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0151] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

[0152] The rubber composition in the examples 1 to 9 was extruded as an insulating material by means of an extruding machine to coat the stranded wire to form an insulating layer, then, the wire was vulcanized in a vulcanization tank, a wire and cable product was obtained after product tests, and then, the product was coated with a rubber sheath in an extruding mode, vulcanized in a high-temperature vulcanization hose and lettered to obtain a wire and cable finished product.

Comparative Example 1

[0153] The processing method was as follows:

[0154] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 100 parts of EPM was added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 100 parts of talcum powder and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent DCP and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0155] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

Comparative Example 2

[0156] The processing method was as follows:

[0157] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 100 parts of EPDM was added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide, 1 part of stearic acid, and 2 parts of an anti-aging agent RD were added, and mixed for 30 s; then, 120 parts of talcum powder, 5 parts of a coloring agent carbon black N550, and 20 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent DCP and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 60 C. to obtain a sheet of which the thickness was about 2.5 mm, and the sheet was allowed to stand for 20 h;

[0158] (2) vulcanization: vulcanization was performed for 30 min at 160 C. under the pressure of 16 MPa, the vulcanized product was allowed to stand for 16 h, and then, various tests were performed.

[0159] The performance test results of the rubber in the examples 1 to 9 and the comparative examples 1 to 2 were as shown in table 2.

TABLE-US-00002 TABLE 2 Performance test results of rubber in examples 1 to 9 and comparative examples 1 to 2 Compar- Compar- ative ative Test example Example Example Example Example example Example Example Example Example Example item 1 1 2 3 4 2 5 6 7 8 9 Hardness 61 66 63 63 64 70 78 68 69 79 72 Tensile 7.1 7.8 7.6 8.6 11.5 8 10.8 8.3 10.8 12.5 12.4 strength/ MPa Elongation 722 533 752 681 663 710 589 642 627 643 653 at break % Volume 2.8 2.7 2.6 2.6 2.6 1.5 2.6 5.3 6.7 7.9 1.8 resistivity/ 10{circumflex over ()}16 10{circumflex over ()}16 10{circumflex over ()}16 10{circumflex over ()}16 10{circumflex over ()}16 10{circumflex over ()}15 10{circumflex over ()}14 10{circumflex over ()}15 10{circumflex over ()}15 10{circumflex over ()}15 10{circumflex over ()}16 .Math. cm After aging (at 150 C. for 168 h) Hardness 65 67 66 66 67 73 80 70 72 81 74 Retention 92 93 92 94 97 83 89 88 92 97 102 rate of tensile strength/ % Retention 94 95 93 98 96 68 82 82 94 94 103 rate of elongation at break/ %

Example 10

[0160] Branched polyethylene No. PER-6 was used.

[0161] The processing method was as follows:

[0162] (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-pressed and mixed for 90 s; 10 parts of zinc oxide was added, and mixed for 30 s; then, 100 parts of calcined clay, 2 parts of vinyl tris(2-methoxyethoxy)silane, and 10 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 1 part of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 80 C., then, the plasticated rubber mix was pressed on a press vulcanizer at 120 C. to obtain a sheet of which the thickness was 0.5 mm, and the sheet was allowed to stand for 20 h;

[0163] (2) crosslinking: radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 200 kGy; the crosslinked product was allowed to stand for 96 h, and then, various tests were performed.

Example 11

[0164] Branched polyethylene No. PER-6 was used.

[0165] The processing method was as follows:

[0166] (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-pressed and mixed for 90 s; 10 parts of zinc oxide was added, and pre-pressed and mixed for 30 s; then, 100 parts of calcined clay, 2 parts of vinyl tris(2-methoxyethoxy)silane, and 10 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 6 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 2 min, and then, the rubber was discharged; the rubber mix was plasticated on an open mill of which the roller temperature was 80 C., then, the plasticated rubber mix was pressed on a press vulcanizer at 120 C. to obtain a sheet of which the thickness was 0.5 mm, and the sheet was allowed to stand for 20 h;

[0167] (2) crosslinking: radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 100 kGy; the crosslinked product was allowed to stand for 96 h, and then, various tests were performed.

Example 12

[0168] Branched polyethylene No. PER-7 was used.

[0169] The processing method was as follows:

[0170] (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-pressed and mixed for 90 s; then, 6 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 3 min, and then, the rubber was discharged; the rubber mix was fully dissolved in a hexane solvent for emulsifying the rubber mix, and then, the solvent was removed to obtain latex;

[0171] (2) crosslinking: the latex was allowed to stand, and dried to form a film, and then, radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 100 kGy; the crosslinked product was allowed to stand for 96 h, and then, various tests were performed.

[0172] The rubber composition in the present example was mixed, dissolved and emulsified to obtain latex, then, a specific mold was dipped in the latex several times and dried, radiation vulcanization was performed, and then, the vulcanized product was subjected to crimping, demolding, tidying, electrical inspection and packaging to finally obtain a condom finished product.

Example 13

[0173] Branched polyethylene No. PER-7 was used.

[0174] The processing method was as follows:

[0175] (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 EPM and 70 parts of branched polyethylene were added, and pre-pressed and mixed for 90 s; then, 6 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 3 min, and then, the rubber was discharged; the rubber mix was fully dissolved in a hexane solvent for emulsifying, and then, the solvent was removed to obtain latex;

[0176] (2) crosslinking: the latex was allowed to stand and dried to form a film, and then, radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 100 kGy; the crosslinked product was allowed to stand for 96 h, and then, various tests were performed.

Example 14

[0177] Branched polyethylene No. PER-7 was used.

[0178] The processing method was as follows:

[0179] (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 EPM and 50 parts of branched polyethylene were added, and pre-pressed and mixed for 90 s; then, 6 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 3 min, and then, the rubber was discharged; the rubber mix was fully dissolved in a hexane solvent for emulsifying, and then, the solvent was removed to obtain latex;

[0180] (2) crosslinking: the latex was allowed to stand and dried to form a film, and then, radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 100 kGy; the crosslinked product was allowed to stand for 96 h, and then, various tests were performed.

Comparative Example 3

[0181] The processing method was as follows:

[0182] (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 EPM was added, and pre-pressed and mixed for 90 s; then, 6 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 3 min, and then, the rubber was discharged; the rubber mix was fully dissolved in a hexane solvent for emulsifying, and then, the solvent was removed to obtain latex;

[0183] (2) crosslinking: the latex was allowed to stand and dried to form a film, and then, radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 100 kGy; the crosslinked product was allowed to stand for 96 h, and then, various tests were performed.

[0184] Performance test results of rubber in the examples 10 to 14 and the comparative example 3 were as shown in table 3.

TABLE-US-00003 TABLE 3 Performance test results of rubber in examples 10 to 14 and comparative example 3 Example Example Example Example Example Comparative Test item 10 11 12 13 14 example 3 Hardness 68 73 Tensile 7.3 13.4 26.9 21.4 16.5 9.3 strength/MPa Elongation at 380 362 823 776 689 613 break % Volume 6.3 6.2 resistivity/ 10{circumflex over ()}16 10{circumflex over ()}16 .Math. cm After aging (at 150 C. for 168 h) Hardness 69 74 Retention rate 101 102 101 102 101 102 of tensile strength/% Retention rate 103 101 102 102 101 102 of elongation at break/%

Example 15

[0185] The present example is a wire. The manufacturing process of the wire was specifically as follows: firstly, stranding was performed; then, the rubber composition in the examples 1 to 9 was extruded as an insulating material by means of an extruding machine to coat the stranded wire to form an insulating layer; then, the wire was vulcanized in a vulcanization tank; and a wire product was after product tests.

Example 16

[0186] The present example is a production method of a cable. The continuous high-temperature vulcanization manufacturing process of the cable was specifically as follows: firstly, stranding was performed; then, the rubber composition in the examples 1 to 9 was extruded as an insulating material by means of an extruding machine to coat the stranded wire to form an insulating layer; then, the wire was vulcanized in a high-temperature vulcanization hose; a cable was formed after tests; then the cable was coated with a rubber sheath in an extruding mode, vulcanized in the high-temperature vulcanization hose and lettered to obtain a cable finished product.

Example 17

[0187] The present example is a condom, and a radiation crosslinking manufacturing process thereof was specifically as follows:

[0188] firstly, the rubber composition in the example 12 was mixed, dissolved and emulsified to obtain latex; then, a specific mold was dipped in the latex several times and dried, and radiation vulcanization was performed; and then, crimping, demolding, tidying, electrical inspection and packaging were performed to finally obtain a finished product.

Example 18

[0189] The present example is a medical rubber plug, and a mold pressing vulcanization production process thereof comprises the following steps:

[0190] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene was added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide and 1 part of stearic acid were added, and mixed for 30 s; then, 100 parts of talcum powder and 10 parts of paraffin oil SUNPAR2280 were added to the rubber, and mixed for 3 min; finally, 3 parts of a crosslinking agent bis(tert-butylperoxydiisopropyl)benzene and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; open milling and batch-out were performed on the rubber mix on an open mill of which the roller temperature was 60 C., the rubber mix was allowed to stand for 20 h, open milling and sheet pressing were performed on the rubber mix on the open mill, and then, the rubber mix was allowed to stand for later use;

[0191] (2) calendering: the rubber mix was calendered on a calender so as to be preformed, and then, cooling was performed;

[0192] (3) vulcanization: the calendered rubber was put into a mold to be subjected to mold pressing vulcanization for 25 min at 160 C. under the pressure of 15 MPa, and after the preset vulcanization time, demolding and cooling were performed;

[0193] (4) after-treatment: trimming, cleaning and silicification were performed to obtain a finished product, and the finished product was packaged and warehoused.

Example 19

[0194] The present example is a condom, and a radiation crosslinking manufacturing process thereof comprises the following steps:

[0195] (1) rubber mixing: the temperature of an internal mixer was set to be 90 C. and the rotor speed was set to be 40 r/min, 100 parts of branched polyethylene PER-10 was added, and pre-pressed and mixed for 90 s; then, 5 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 3 min, and then, the rubber was discharged; the rubber mix was fully dissolved in a hexane solvent for emulsifying, and then, the solvent was removed to obtain latex;

[0196] (2) forming: a specific mold was dipped in the latex several times and dried so as to be formed;

[0197] (3) crosslinking: radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 100 kGy;

[0198] (4) after-treatment: crimping, demolding, tidying, electrical inspection and packaging were performed to finally obtain a condom finished product.

[0199] The obtained condom rubber has a tensile strength of 28.9 MPa and an elongation at break of 683%.

Example 20

[0200] The present example is a condom and a radiation crosslinking manufacturing process thereof comprises the following steps:

[0201] (1) rubber mixing: the temperature of an internal mixer was set to be 90 C. and the rotor speed was set to be 40 r/min, 100 parts of branched polyethylene PER-12 was added, and pre-pressed and mixed for 90 s; then, 6 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 3 min, and then, the rubber was discharged; the rubber mix was fully dissolved in a hexane solvent for emulsifying, and then, the solvent was removed to obtain latex;

[0202] (2) forming: a specific mold was dipped in the latex several times and dried so as to be formed;

[0203] (3) crosslinking: radiation crosslinking was performed in air at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 120 kGy;

[0204] (4) after-treatment: crimping, demolding, tidying, electrical inspection and packaging were performed to finally obtain a condom finished product.

[0205] The obtained condom rubber has a tensile strength of 30.6 MPa and an elongation at break of 712%.

Example 21

[0206] The present example is a medical catheter, adopting a production process of extrusion forming and high-temperature steam vulcanization which specifically comprises the following steps:

[0207] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene PER-11 was added, and pre-pressed and mixed for 90 s; then, 10 parts of colorless paraffin oil was added to the rubber, and mixed for 3 min; finally, 5 parts of a crosslinking agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (paste, effective component: 50%) and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged; open milling and batch-out were performed on the rubber mix on an open mill of which the roller temperature was 60 C., and then, the rubber mix was allowed to stand for 20 h for later use;

[0208] (2) extrusion: extrusion forming was performed on the rubber mix on an extruding machine, wherein the rotation speed of the extruding machine was 50 r/min, and the temperature of a machine head was 90 C.;

[0209] (3) crosslinking: firstly, high-temperature steam vulcanization was performed on the extruded rubber for 10 min at 170 C., and then, secondary vulcanization was performed for 4 h at 160 C.;

[0210] (4) after-treatment: cleaning was performed to obtain a finished product, and the finished product was packaged and warehoused.

Example 22

[0211] The present example is a medical catheter, adopting a production process of extrusion forming and radiation crosslinking which specifically comprises the following steps

[0212] (1) rubber mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, 100 parts of branched polyethylene PER-5 was added, and pre-pressed and mixed for 90 s; then, 4 parts of a radiation-sensitized auxiliary crosslinking agent trimethylolpropane trimethacrylate was added, and mixed for 2 min, and then, the rubber was discharged; open milling and batch-out were performed on the rubber mix on an open mill of which the roller temperature was 60 C., and then, the rubber mix was allowed to stand for later use;

[0213] (2) extrusion: extrusion forming was performed on the rubber mix on an extruding machine, wherein the rotation speed of the extruding machine was 50 r/min, and the temperature of a machine head was 90 C.;

[0214] (3) vulcanization: radiation crosslinking was performed on the extruded rubber at normal temperature, wherein the electron beam energy for radiation was 1.0 MeV, the beam intensity was 1.0 mA, and the radiation dose was 120 kGy;

[0215] (4) after-treatment: cleaning was performed to obtain a finished product, and the finished product was packaged and warehoused.

[0216] Performance Data Analysis:

[0217] 1. Comparing the example 3 and the example 4 with the comparative example 1, it can be seen that as the proportion of the branched polyethylene in the rubber matrix increases, the mechanical strength of the vulcanized rubber was significantly improved, and the aging resistance and electrical insulation properties were maintained at the same level;

[0218] 2. Comparing the example 7 and the example 9 with the comparative example 2, it can be seen that as the proportion of the branched polyethylene in the rubber matrix increases, the mechanical strength, electrical insulation properties and aging resistance of the vulcanized rubber were improved to different degrees.

[0219] 3. It can be seen from the example 10 and the example 11 that the electrical insulation properties of the vulcanized rubber obtained by radiation crosslinking were better than the electrical insulation properties of the vulcanized rubber obtained by peroxide crosslinking or sulfur crosslinking. Furthermore, it can be seen from the examples 12, 13 and 14 and the comparative example 3 that the branched polyethylene also has better mechanical strength than the EPM in a radiation crosslinking system, and the currently measured mechanical strength can be as high as 26.9 MPa which was close to the mechanical strength of natural latex radiation vulcanization, at least indicating that the branched polyethylene can be used for producing traditional natural latex products, such as condoms and gloves, by means of a radiation crosslinking process.

[0220] The comparison of the vulcanization performance test data of the examples 23 and 24 and the comparative example 4 below shows that the branched polyethylene has an excellent crosslinking capability.

[0221] The rubber matrix used in the example 23 includes 100 parts of PER-12. The rubber matrix used in the example 24 includes 50 parts of PER-4 and 50 parts of EPDM, wherein the Mooney viscosity ML(1+4) at 125 C. was 60, the ethylene content was 70%, and the ENB content was 5%. The rubber matrix used in the comparative example 3 includes 100 parts of EPDM used in the example 24. Other formulas were identical.

[0222] The processing steps of three rubber compositions were as follows:

[0223] (1) mixing: the temperature of an internal mixer was set to be 80 C. and the rotor speed was set to be 50 r/min, a rubber matrix was added, and pre-pressed and mixed for 90 s; 5 parts of zinc oxide and 1 part of stearic acid were added, and mixed for 1 min;

[0224] (2) then, 100 parts of talcum powder and 20 parts of paraffin oil were added to the rubber, and mixed for 3 min;

[0225] (3) finally, 7 parts of a crosslinking agent DCP-40 and 1 part of an auxiliary crosslinking agent TAIC were added, and mixed for 2 min, and then, the rubber was discharged;

[0226] (4) the rubber mix was plasticated on an open mill of which the roller temperature was 40 C. to obtain a sheet of which the thickness was about 2.5 mm, the sheet was allowed to stand for 20 h, and then, vulcanization performance was tested;

[0227] Test conditions: 175 C. 30 min. Test results were as follows:

TABLE-US-00004 Comparative Example 23 Example 24 example 4 ML, dN .Math. m 0.81 0.72 0.68 MH, dN .Math. m 13.14 13.24 13.36 MH ML, dN .Math. m 12.33 12.52 12.68 Tc90, min 5.4 6.2 6.8

[0228] The Tc90 of the rubber composition in the example 23 was the shortest and was nearly 20% shorter than the Tc90 of the rubber composition in the comparative example 3, and the MH-ML value of the rubber composition in the example 23 was close to the MH-ML value of the rubber composition in the comparative example 3, indicating that the crosslinking density of the rubber composition in the example 23 was close to the crosslinking density of the rubber composition in the comparative example 3. The results can preliminarily show that the branched polyethylene used in the present invention was close to or even better than the conventional EPDM in crosslinking capability.

[0229] Although the present invention has been described in detail through the foregoing examples, it should be understood by a person of ordinary skill in the art that modifications or improvements may be made based on the contents disclosed herein without departing from the spirit and scope of the present invention, and such modifications and improvements shall all fall within the spirit and scope of the present invention.