阅读说明：本技术 绝缘性良好的橡胶组合物及加工方法与应用 (Rubber composition with good insulation property, processing method and application ) 是由 不公告发明人 于 2018-07-13 设计创作，主要内容包括：本发明公开了一种绝缘性良好的橡胶组合物及加工方法与应用,该橡胶组合物包括：橡胶基体和配合组份,按重量份计,所述每100份橡胶基体中包含50～95份氯(磺)化聚乙烯橡胶、5～50份高度支化聚乙烯,0～30份乙丙橡胶；其中,高度支化聚乙烯的支化度不低于50个支链/1000个碳；所述配合组份包含硫化体系。本发明中提供的橡胶组合物改善了氯(磺)化聚乙烯的电绝缘性能,使之更加适用于对电绝缘性有较高要求的应用场合。(The invention discloses a rubber composition with good insulation property, a processing method and application thereof, wherein the rubber composition comprises the following components: the rubber comprises a rubber matrix and matching components, wherein each 100 parts of the rubber matrix comprises 50-95 parts of chloro (sulfonated) polyethylene rubber, 5-50 parts of highly branched polyethylene and 0-30 parts of ethylene propylene rubber in parts by weight; wherein the highly branched polyethylene has a degree of branching of not less than 50 branches/1000 carbons; the compounding component comprises a vulcanization system. The rubber composition provided by the invention improves the electrical insulation performance of the chlorosulfonated polyethylene, so that the chlorosulfonated polyethylene is more suitable for application occasions with higher requirements on electrical insulation performance.)

1. A rubber composition comprises a rubber matrix and a matching component, and is characterized in that each 100 parts of the rubber matrix comprises 50-95 parts of chloro (sulfonated) polyethylene rubber, 5-50 parts of highly branched polyethylene and 0-30 parts of ethylene propylene rubber in parts by weight; the compounding component comprises a vulcanization system.

2. The rubber composition of claim 1, wherein the highly branched polyethylene is an ethylene homopolymer having a degree of branching of not less than 50 branches per 1000 carbons.

3. The rubber composition of claim 2, wherein the highly branched polyethylene has a degree of branching of 60 to 130 branches per 1000 carbons.

4. The rubber composition of claim 2, wherein the highly branched polyethylene has a degree of branching of 70 to 120 branches/1000 carbons.

5. The rubber composition of claim 1, wherein the ethylene-propylene rubber is ethylene-propylene-diene monomer rubber.

6. The rubber composition according to claim 1, wherein the rubber matrix further comprises 1-20 parts by weight of a compatibilizer, and the compatibilizer is a polarization-modified reaction product of ethylene propylene rubber or highly branched polyethylene.

7. The rubber composition according to claim 6, wherein the compatibilizer is chlorinated polyethylene LCPE with a chlorine content of 2% to 20%, and the polyethylene raw material for preparing the chlorinated polyethylene LCPE is at least one selected from high-density polyethylene, low-density polyethylene and highly branched polyethylene.

8. The rubber composition of claim 1, wherein the cure system is selected from at least one of a peroxide cure system, a thiourea cure system, a thiadiazole cure system, a metal oxide cure system, and a radiation cure sensitized system.

9. The rubber composition of claim 8, wherein the curing system is a peroxide curing system, the amount of the peroxide is 1-10 parts by weight based on 100 parts by weight of the rubber matrix, and the peroxide crosslinking agent is at least one of di-tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, 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-3-hexyne, bis (tert-butylperoxyisopropyl) benzene, 2, 5-dimethyl-2, 5-di (peroxybenzoic acid) hexane, tert-butyl peroxybenzoate and tert-butylperoxy-2-ethylhexyl carbonate.

10. The rubber composition of claim 9, wherein the peroxide curing system comprises 0.2-20 parts by weight of an auxiliary crosslinking agent, and the auxiliary crosslinking agent comprises at least one of triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, N '-m-phenylene bismaleimide, N' -difurfurylacetone, 1, 2-polybutadiene, metal salts of unsaturated carboxylic acids, and sulfur.

11. The rubber composition according to claim 1, wherein the compounding ingredients comprise, based on 100 parts by weight of the rubber base, 10 to 200 parts of a reinforcing filler, 0 to 80 parts of a plasticizer, 3 to 30 parts of a metal oxide, 0 to 3 parts of stearic acid, 0 to 15 parts of a surface modifier, 1 to 15 parts of a stabilizer, 0 to 150 parts of a flame retardant, and 0 to 20 parts of a foaming agent.

12. A wire or cable having an insulating layer, wherein a rubber for the insulating layer comprises the rubber composition according to any one of claims 1 to 11.

13. A wire or cable having a sheath layer, wherein the rubber for the sheath layer comprises the rubber composition according to any one of claims 1 to 11.

Technical Field

The invention belongs to the technical field of rubber, and particularly relates to a rubber composition with good insulation, a processing method and application thereof.

Background

The chloro (sulfonated) polyethylene rubber is a polar special rubber with excellent oil resistance, flame retardance and chemical stability, and is mainly applied to the field of electric wires and cables, but the chloro (sulfonated) polyethylene rubber cannot be well applied to occasions with higher requirements on electric insulativity due to poor electric insulating property of the chloro (sulfonated) polyethylene rubber.

Disclosure of Invention

The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a rubber composition which can improve both electrical insulation properties and cost. The technical scheme of the invention is that the highly branched polyethylene with completely saturated molecular structure and simple production process is adopted to replace part or all of ethylene propylene rubber and is used together with chlorinated (sulfonated) polyethylene rubber to improve the electrical insulation performance of the ethylene propylene rubber.

The technical scheme of the invention is as follows: a rubber composition comprises a rubber matrix and matching components, wherein each 100 parts of the rubber matrix comprises 50-95 parts of chloro (sulfonated) polyethylene rubber, 5-50 parts of highly branched polyethylene and 0-30 parts of ethylene propylene rubber in parts by weight; wherein the highly branched polyethylene is an ethylene homopolymer having a degree of branching of not less than 50 branches/1000 carbons; the compounding component comprises a vulcanization system.

The further technical scheme is that the dosage of the chloro (sulfonated) polyethylene rubber in each 100 parts of rubber matrix is preferably 50-90 parts, and more preferably 60-80 parts; the amount of the highly branched polyethylene is preferably 10 to 50 parts, more preferably 20 to 40 parts, per 100 parts of the rubber matrix.

The highly Branched Polyethylene used in the invention is an ethylene homopolymer with the branching degree of not less than 50 branches/1000 carbons, which can be called Branched Polyethylene or Branched PE, and the synthesis method of the highly Branched Polyethylene is mainly obtained by catalyzing ethylene homopolymerization by a late transition metal catalyst based on a chain walking mechanism, and the preferred late transition metal catalyst can be one of (alpha-diimine) nickel/palladium catalysts. The essence of the chain walking mechanism means that a late transition metal catalyst, such as an (alpha-diimine) nickel/palladium catalyst, is easy to generate beta-hydrogen elimination reaction and reinsertion reaction in the process of catalyzing olefin polymerization, so that branched chains are generated. The branched chain of the main chain of the highly branched polyethylene can have different carbon atoms, and specifically, the number of the carbon atoms can be 1-6, or more.

The production cost of the (alpha-diimine) nickel catalyst is obviously lower than that of the (alpha-diimine) palladium catalyst, and the catalyst is more suitable for industrial application, so the invention preferably selects the highly branched polyethylene prepared by ethylene polymerization catalyzed by the (alpha-diimine) nickel catalyst.

The branching degree of the highly branched polyethylene raw material used in the invention is not less than 50 branches/1000 carbons, and the weight average molecular weight is not less than 6.6 ten thousand; the degree of branching is more preferably 60 to 130 branches/1000 carbons, and the weight average molecular weight is more preferably 6.6 to 51.8 ten thousand; the degree of branching is more preferably 70 to 120 branches/1000 carbons, and the weight average molecular weight is more preferably 8.2 to 43.6 ten thousand; the Mooney viscosity ML (1+4) at 125 ℃ is preferably 6 to 102, and more preferably 12 to 93.

The ethylene-propylene rubber used in the present invention is ethylene-propylene-diene rubber or ethylene-propylene-diene rubber, preferably ethylene-propylene-diene rubber, and the third monomer is selected from 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, dicyclopentadiene, 1, 4-hexadiene, 1, 5-hexadiene, 1, 4-pentadiene, 2-methyl-1, 4-pentadiene, 3-methyl-1, 4-hexadiene, 4-methyl-1, 4-hexadiene, 1, 9-decadiene, 5-methylene-2-norbornene, 5-amylidene-2-norbornene, 1, 5-cyclooctadiene, 1, 4-cyclooctadiene, etc., preferably 5-ethylidene-2-norbornene, 1, 4-cyclooctadiene, etc, 5-vinyl-2-norbornene, dicyclopentadiene, 1, 4-hexadiene.

The polyethylene feedstock for the preparation of the chloro (sulfonated) polyethylene used in the present invention may be selected from at least one of high density polyethylene, low density polyethylene and highly branched polyethylene.

The further technical scheme is that in order to improve the compatibility of the rubber matrix, 1-20 parts of compatibilizer is further contained in every 100 parts by weight of rubber matrix, and the compatibilizer is a reaction product obtained by polarization modification of ethylene propylene rubber or highly branched polyethylene. The polar monomer used for polarization modification comprises at least one of Maleic Anhydride (MAH), Methacrylic Acid (MA), Acrylic Acid (AA), Itaconic Acid (IA), Fumaric Acid (FA), isocyanate, Glycidyl Methacrylate (GMA), Methyl Methacrylate (MMA), dibutyl fumarate (DBF), beta-hydroxyethyl methacrylate (HEMA), dibutyl maleate (DBM), diethyl maleate (DEM), elemental halogen, halogen-containing compound, sulfur-containing compound, Vinyltrimethoxysilane (VTMS), Vinyltriethoxysilane (VTES), 3-methacryloxypropyltrimethoxysilane (VMMS), styrene (St), alpha-methylstyrene (alpha-MSt), Acrylonitrile (AN).

The preferable compatibilizer is chlorinated polyethylene LCPE with chlorine content lower than chlorine (sulfonated) polyethylene rubber, the chlorine content of the LCPE is 2-20%, and the preferable compatibilizer is 5-15%, the raw material for preparing the LCPE can be high-density polyethylene or low-density polyethylene for preparing the conventional chlorine (sulfonated) polyethylene rubber, and also can be highly branched polyethylene used in the invention, and the raw material for preparing the polyethylene of the LCPE is preferably highly branched polyethylene. The compatibilizer LCPE using the highly branched polyethylene as the raw material has a better compatibilizer effect on the highly polar chlorinated (sulfonated) polyethylene and the nonpolar ethylene propylene rubber or the highly branched polyethylene than the compatibilizer LCPE using the traditional high density polyethylene or low density polyethylene as the raw material.

The rubber composition of the present invention may have a vulcanizing system selected from a peroxide vulcanizing system, a thiourea vulcanizing system, a thiadiazole vulcanizing system, a triazole dimercaptoamine salt vulcanizing system, a metal oxide vulcanizing system, an epoxy resin vulcanizing system, a maleimide vulcanizing system, a radiation vulcanization sensitization system, etc., and preferably has at least one of a peroxide vulcanizing system, a thiourea vulcanizing system, a metal oxide vulcanizing system, and a radiation vulcanization sensitization system.

The peroxide vulcanization system comprises a peroxide crosslinking agent and an auxiliary crosslinking agent, and the further technical scheme is that the amount of the peroxide crosslinking agent is 1-10 parts and the amount of the auxiliary crosslinking agent is 0.2-20 parts based on 100 parts by weight of the rubber matrix. Wherein the peroxide crosslinking agent comprises at least one of di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, 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 (BIBP), 2, 5-dimethyl-2, 5-di (benzoylperoxy) hexane (DBPMH), tert-butyl peroxybenzoate and tert-butylperoxy-2-ethylhexyl carbonate, and the auxiliary crosslinking agent comprises triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, tert-butylcumyl peroxide, Ethyl dimethacrylate, triethylene dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, N '-m-phenylene bismaleimide (HVA-2), N' -difurfurylideneacetone, 1, 2-polybutadiene, p-quinonedioxime, sulfur, and at least one of metal salts of unsaturated carboxylic acids including at least one of zinc acrylate, zinc methacrylate (ZDMA), magnesium methacrylate, calcium methacrylate, and aluminum methacrylate. The addition of a suitable amount of metal salt of unsaturated carboxylic acid such as zinc methacrylate is effective in improving the vulcanization properties and the physical and mechanical properties, especially the tensile strength, of the vulcanizate.

The thiourea curing system is composed of thiourea and sulfur, wherein the thiourea can be selected from ethylthiourea or ethylenethiourea.

The thiadiazole vulcanization system and the triazole dimercaptoamine salt vulcanization system are suitable for rubber compositions with vulcanized rubber matrixes with higher halogen content. The thiadiazole vulcanization system consists of a cross-linking agent and an accelerant, wherein the cross-linking agent is mainly a thiadiazole derivative cross-linking agent, commonly comprises ECHO.A, TDD, PT75, TDDS and the like, and commonly comprises Vanax 808, EataAccelDH, NC, Accel 903, BF and the like. And mixing with a certain amount of acid acceptor such as high-activity magnesium oxide or superfine magnesium hydroxide.

The triazole dimercapto amine salt vulcanizing system is a single substance integrating effective groups of a thiadiazole vulcanizing agent and an accelerant (a condensate of n-butyl aldehyde and aniline), overcomes the defect of irregular distribution of bonds after the thiadiazole and the accelerant crosslink rubber, and enables the rubber crosslinked body to be a stable structure. Compared with a thiadiazole system, the salt changes the pH value of the system due to the introduction of special groups, changes strong acidity into neutrality, changes the adverse effect of acidic fillers on the system, and enables rubber to have more chemical activity during crosslinking. Therefore, the physical property or the chemical property of the cross-linked rubber of the system is improved. The vulcanizing agent is suitable for the low-temperature pressureless low-pressure vulcanizing process conditions, has high vulcanizing speed, small addition amount, no decomposition in the vulcanizing temperature, no odor, environmental protection and no toxicity. Representative products are: vulcanizing agent FSH, cross-linking agent TEHC.

The metal oxide vulcanization system is suitable for a rubber composition containing chlorosulfonated polyethylene, which contains zinc oxide, and further contains magnesium oxide having the function of a scorch retarder and stearic acid having the function of assisting dispersion of the metal oxide and adjusting the vulcanization speed.

The main component of the radiation vulcanization sensitization system is a radiation sensitizer which can be selected from triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate and the like. The radiation sensitization system is particularly suitable for the application field of wires and cables with requirements on electrical insulation performance or medical rubber products with higher requirements on material cleanliness.

The rubber composition further comprises 10-200 parts of reinforcing filler, 0-80 parts of plasticizer, 3-30 parts of metal oxide, 0-3 parts of stearic acid, 0-15 parts of surface modifier, 1-15 parts of stabilizer, 0-150 parts of flame retardant and 0-20 parts of foaming agent by 100 parts by weight of rubber matrix.

The further technical scheme is that the reinforcing filler comprises at least one of carbon black, white carbon black, calcium carbonate, calcined argil, talcum powder, magnesium silicate, aluminum silicate, magnesium carbonate, titanium dioxide, montmorillonite, short fiber, kaolin and bentonite.

The further technical scheme is that the plasticizer comprises at least one of pine tar, engine oil, naphthenic oil, paraffin oil, aromatic oil, liquid 1, 2-polybutadiene, liquid polyisobutylene, ethylene glycol dimethacrylate, liquid ethylene propylene rubber, coumarone, RX-80, stearic acid, paraffin, chlorinated paraffin, dioctyl adipate, dioctyl sebacate, epoxidized soybean oil, dibutyl phthalate, dioctyl phthalate, diisodecyl phthalate, ditridecyl phthalate and trioctyl trimellitate. For improving the viscosity, it is also preferable to use a plasticizer having a thickening effect, such as pine tar, coumarone, RX-80, liquid polyisobutylene, ethylene glycol dimethacrylate, etc. In order to improve cold resistance, dioctyl adipate, dioctyl sebacate, dioctyl phthalate, and the like can be preferably used. For halogen-containing rubber matrices, epoxidized soybean oil has the effect of stabilizing the rubber matrix during processing.

The further technical scheme is that the metal oxide comprises at least one of zinc oxide, magnesium oxide, aluminum oxide, lead oxide and calcium oxide. The metal oxide may assist in crosslinking and absorb hydrogen chloride or hydrogen bromide.

The stabilizer is selected from 2,2, 4-trimethyl-1, 2-dihydroquinoline polymer (RD), 6-ethoxy-2, 2, 4-trimethyl-1, 2-dihydroquinoline (AW), 2-Mercaptobenzimidazole (MB), N-phenyl-N ' -cyclohexyl-p-phenylenediamine (4010), N-isopropyl-N ' -phenyl-p-phenylenediamine (4010NA), N- (1, 3-dimethyl) butyl-N ' -phenyl-p-phenylenediamine (4020), etc., and the stabilizer can be further selected from basic lead salt compounds, metal soap compounds, organotin compounds, epoxy compounds, phosphite compounds, etc. for rubber compositions with high halogen content in the rubber matrix, And polyhydric alcohol compounds, wherein the basic lead salt compound is selected from lead stearate, dibasic lead titanate, basic lead silicate, lead phthalate, and the like.

The further technical scheme is that the flame retardant comprises at least one of pentaerythritol, ammonium polyphosphate, triethyl phosphate, aluminum hydroxide, magnesium hydroxide, zinc borate, antimony trioxide, zinc stearate, titanate, decabromodiphenyl ether, hydroxide modified by a silane coupling agent and red phosphorus. The aluminum hydroxide, the magnesium hydroxide and the hydroxide modified by the silane coupling agent are respectively nano aluminum oxide and nano magnesium hydroxide and nano hydroxide modified by the silane coupling agent, and the red phosphorus is microencapsulated red phosphorus.

The further technical proposal is that the surface modifier comprises at least one of polyethylene glycol, diphenyl silanediol, triethanolamine, silane coupling agent and titanate coupling agent.

The foaming agent comprises at least one of sodium bicarbonate, Azodicarbonamide (AC), dinitrosopentamethylenetetramine (H), diphenyl sulfonyl hydrazide ether (OBSH), benzenesulfonyl hydrazide (BSH), urea and a microcapsule type foaming agent containing low-boiling-point hydrocarbon.

The rubber composition of the present invention may be present in the form of an uncrosslinked rubber compound, and may be present in the form of a vulcanized rubber after further crosslinking reaction has occurred. The vulcanized rubber may also be referred to simply as vulcanized rubber.

The invention also provides a method A for processing the rubber composition into a rubber compound by adopting a reverse mixing method, which comprises the following steps:

(1) setting the temperature of an internal mixer and the rotating speed of a rotor;

(2) sequentially adding the components except the vulcanization system in the matching system into an internal mixer according to the sequence of the dry auxiliary agent and the liquid auxiliary agent;

(3) putting the rubber matrix components into an internal mixer;

(4) after the mixing power is stable, putting a vulcanization system, and discharging rubber after mixing;

(5) thin-passing, blanking, cooling, standing for 24 hours and back-refining to obtain the finished product.

And (5) preparing a sample and performing performance test according to the test standard after the sheet is taken out.

When the Mooney viscosities of different components in the rubber matrix are greatly different, the invention also provides another processing method B of the rubber composition, which specifically comprises the steps of dividing various rubber matrices into at least two groups by a master batch method, preparing mixing master batch with approximate Mooney viscosities by the rubber matrices of each group according to the steps of 1-3 in the method A, then putting the mixing master batches into an internal mixer or an open mill together for mixing, then adding a vulcanization system, and thinly passing through a lower sheet after uniform mixing.

The invention also provides a wire and cable, wherein the insulating rubber used for the insulating layer of the wire and cable comprises the rubber composition. Common electric wires and cables can be selected from parallel twin-core wires, parallel triple-core wires or rubber-sheathed flexible cables mainly comprising air-conditioning wires, and further the electric wires and cables are mainly selected from medium-low voltage electric wires and cables. In particular to a medium-sized rubber jacketed flexible cable.

The invention also provides a wire or cable which is provided with a sheath layer, wherein the rubber used for the sheath layer comprises the rubber composition. Common electric wires and cables can be selected from double-core parallel wires, three-core parallel wires or rubber jacketed flexible cables taking air-conditioning wires as main bodies, further the electric wires and cables can be selected from mining cables, marine cables, household appliance rubber jacketed wires, flexible cables for electrical equipment, flame-retardant rubber jacketed wires for buildings, automobile ignition wires, electric welding machine cables and the like, and also can be selected from electric wires and cables applied to other occasions with requirements on flame retardance, oil resistance and weather resistance, such as medium-sized and heavy-sized rubber jacketed flat cables for cranes, elevators, power station coal conveying rail cars and the like.

The invention has the beneficial effects that:

1. the electric insulation performance of the chloro (sulfonated) polyethylene rubber can be optimized in a low-cost mode, and the obtained rubber composition is more suitable for application occasions with higher requirements on electric insulation performance;

2. the rubber composition of the present invention is superior to chlorinated polyethylene rubber in compression set resistance, low temperature resistance, mechanical strength, etc., and thus may be used in various fields with high requirement for these properties.

Detailed Description

The following examples are given to further illustrate the present invention, but not to limit the scope of the present invention, and those skilled in the art should be able to make certain insubstantial modifications and adaptations of the invention based on the teachings of the present invention.