Rubber composition, processing method thereof, sealing element using the same
The invention discloses a rubber composition and a method for processing the rubber composition, and a sealing element using the rubber composition and a production method thereof. The rubber composition comprises, in parts by weight, 100 parts of a rubber matrix, 2-20 parts of a cross-linking system, 60-300 parts of a reinforcing filler, 20-170 parts of a plasticizer and 3-25 parts of a metal oxide, wherein, the rubber matrix comprises a branched polyethylene with a content represented as A, in which 0<A≤100 parts, and both an EPM rubber and an EPDM rubber with a total content represented as B, in which 0≤B<100 parts. The invention provides a sealing element with good compression set resistance.
1. A rubber composition, comprising a rubber matrix and certain essential components, wherein, said rubber matrix comprises, in parts by weight,
a branched polyethylene with a content represented as A, 10≤A≤100 parts, and
an EPM and an EPDM, with a total content represented as B, 0≤B<100 parts;
wherein A+B is equal to 100 total parts;
wherein, with respect to 100 parts by weight of the total amount of said rubber matrix, said certain essential components comprise 2˜20 parts of a cross-linking system, 60˜300 parts of a reinforcing filler, 20˜170 parts of a plasticizer and 3-25 parts of a metal oxide;
wherein, said branched polyethylene comprises an ethylene homopolymer having a branching degree of from 50 to 60 branches/1000 carbon atoms, a weight-average molecular weight of from 250,000 to 400,000, and a mooney viscosity ML (1+4) 125° C. which is not less than 2; said cross-linking system comprises a cross-linking agent and an assistant cross-linking agent; and
wherein the branched polyethylene is an elastomer.
2. The rubber composition according to claim 1 , wherein the rubber matrix comprises a non-zero amount of EPM and a non-zero amount of EPDM.
3. The rubber composition according to claim 1 , wherein, said cross-linking agent comprises at least one of a sulfur cross-linking agent and a peroxide cross-linking agent, and said peroxide cross-linking 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-butyl peroxy)hexane, 2,5-dimethyl-2,5-di(tert-butyl peroxy)hexyne-3, bis(tert-butyl peroxy isopropyl)benzene, 2,5-dimethyl-2,5-bis(benzoyl peroxy)hexane, tert-butyl peroxybenzoate and tert-butylperoxy-2-ethylhexyl carbonate.
4. The rubber composition according to claim 1 , wherein, said assistant cross-linking agent comprises at least one of triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, triallyl trimellitate, trimethacrylic acid trimethylolpropane ester, N,N′-m-phenylene bismaleimide, N,N′-bis-indenylene acetonone, 1,2-polybutadiene, sulfur and unsaturated carboxylic acid metal salts.
5. The rubber composition according to claim 1 , wherein, said cross-linking system further comprises 0˜3 parts of a vulcanization accelerator, with respect to 100 parts by weight of the total amount of said rubber matrix; said vulcanization accelerator comprises at least one of 2-thiol benzothiazole, dibenzothiazole disulfide, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethyl thiuram disulfide, zinc di-n-butyldithiocarbamate, N-cyclohexyl-2-benzothiazolyl sulfenamide, N,N-dicyclohexyl-2-phenylthiazolyl sulfenamide, bismaleimide and ethylene thiourea.
6. The rubber composition according to claim 1 , wherein, said plasticizer comprises at least one of stearic acid, pine tar, motor oil, naphthenic oil, paraffin oil, coumarone resin, and paraffin wax.
7. The rubber composition according to claim 1 , wherein, said reinforcing filler comprises at least one of carbon black, calcium carbonate, calcined clay, magnesium silicate, aluminum silicate and magnesium carbonate.
8. The rubber composition according to claim 1 , wherein, said metal oxide comprises at least one of zinc oxide, magnesium oxide and calcium oxide.
9. The rubber composition according to claim 1 , wherein, said rubber composition further comprises auxiliary components; said auxiliary components comprise 1˜3 parts of a stabilizer and 1˜10 parts of polyethylene glycol by mass, with respect to 100 parts by weight of the total amount of said rubber matrix.
10. The rubber composition according to claim 9 , wherein, 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).
11. The rubber composition according to claim 9 , wherein, said polyethylene glycol comprises at least one of polyethylene glycol having a molecular weight of 2000, 3400, and 4000.
12. A sealing element, wherein the rubber compound used for said sealing element comprises said rubber composition according to claim 1 .
13. The sealing element according to claim 12 , wherein, said sealing element is a sealing strip, and the rubber compound used for said sealing element comprises said rubber composition.
14. A composite sealing strip with both foamed and solid parts, wherein the rubber compound used for the solid part of said composite sealing strip comprises said rubber composition according to claim 1 .