WO2018130190A1

WO2018130190A1 - Rubber-based electrically-conductive nonlinear insulating material and processing method therefor

Info

Publication number: WO2018130190A1
Application number: PCT/CN2018/072357
Authority: WO
Inventors: 徐涛; 傅智盛; 吴安洋
Original assignee: 杭州星庐科技有限公司
Priority date: 2017-01-13
Filing date: 2018-01-12
Publication date: 2018-07-19

Abstract

Disclosed are a rubber-based electrically-conductive nonlinear insulating material and a processing method therefor. The electrically-conductive nonlinear insulating material comprises a rubber composite. The rubber composite comprises : a rubber substrate and essential components. The rubber substrate comprises : branched polyethylene, the content thereof being a : 0 < a ≤ 100 parts, ethylene propylene monomer rubber and ethylene propylene diene monomer rubber, the content thereof being b : 0 ≤ b < 100 parts. The essential components comprises : a crosslinking agent 1.5-8 parts, a nonlinear functional filler 10-50 parts, and a reinforcing filler 5-40 parts. The beneficial effect is such that, compared with an existing ethylene propylene rubber-based electrically-conductive nonlinear insulating material, the electrically-conductive nonlinear insulating material containing the rubber composite has great insulating effects and mechanical performance.

Description

Rubber-based electric conductivity nonlinear insulating material and processing method thereof

Technical field:

The invention belongs to the technical field of rubber, and in particular relates to a base conductance nonlinear insulating material comprising a rubber composition and a processing method thereof.

Background technique

Existing polyolefin-based nonlinear composites are prepared by blending a polyolefin resin with one or more fillers, having a non-linear conductance or (and) a nonlinear dielectric constant. Due to the properties of the base resin polyolefin itself, the application field of polyolefin-based nonlinear composite materials is limited and cannot be applied to some occasions where rubber products are required.

Ethylene-propylene rubber has the advantages of electrical insulation, ozone resistance, aging resistance, water repellency and combustion resistance, and is widely used in the field of electrical insulation. Compared with silicone rubber, ethylene propylene rubber has the advantages of good chemical corrosion resistance, high mechanical strength and low price.

It has been reported in the literature that one or more non-linear functional fillers are added to ethylene propylene rubber, and then reinforced by adding an appropriate amount of reinforcing agent. After vulcanization, it can also be used as a conductive non-linear insulating material, and has become a widely used conductance. Nonlinear insulating material. Ethylene-propylene rubber can be divided into two categories: ethylene-propylene rubber (EPM) and EPDM. Compared with the two, EPM has better electrical insulation and aging resistance, but the vulcanization rate is too slow. The mechanical properties are low; while EPDM has a faster vulcanization rate and higher mechanical properties, but the electrical insulation performance is reduced, so there are some shortcomings in practical applications.

How to improve the aging resistance, mechanical properties and electrical insulation properties of ethylene propylene rubber is a technical problem to be solved.

Ethylene-propylene rubber is a synthetic rubber with saturated molecular chain. It can be divided into two major categories: ethylene-propylene rubber and EPDM rubber. Both of them have good aging resistance. They are commonly used in ethylene-propylene rubber products. It is EPDM rubber, but because EPDM rubber contains a third monomer, the molecular chain contains double bonds, and the ethylene-propylene rubber molecular chain is completely saturated, so the ethylene-propylene rubber has more excellent resistance to aging. Sex, therefore, in the case of high requirements for aging resistance, it is a common technical solution to improve the aging resistance of EPDM by using ethylene propylene diene rubber together. However, the mechanical strength of the binary ethylene propylene rubber is low, which will affect the overall physical and mechanical properties.

Diethylene propylene rubber is a copolymer of ethylene and propylene and belongs to the copolymer of ethylene and α-olefin. Ethylene and α-olefin copolymers are polymers containing only hydrocarbon elements and saturated molecular chains. The common types of carbon atoms in such polymers are generally classified into primary, secondary and tertiary carbons, while tertiary carbons are the most It is easy to be trapped by hydrogen to form free radicals, so the ratio of tertiary carbon atoms to all carbon atoms is generally considered to be a major factor affecting the aging resistance of ethylene and α-olefin copolymers. The lower the ratio, the better the aging resistance. The ratio can be expressed by the degree of branching. For example, a diethylene propylene rubber having a propylene content of 60% by weight can be calculated to contain 200 propylene units per 1000 carbon atoms, that is, 200 tertiary carbon atoms or 200. One methyl branch, so its degree of branching is 200 branches / 1000 carbons. Ethylene ethylene propylene rubber generally has a weight percentage of 40% to 65% or 40% to 60%, so its branching degree is generally 117 to 200 branches/1000 carbons or 133 to 200 branches/ This degree of branching can be considered to be higher than other common ethylene and alpha-olefin copolymers in the 1000 carbon range.

In the prior art, the α-olefin in the common ethylene and α-olefin copolymer may be an α-olefin having a carbon number of not less than 4 in addition to propylene, and may be selected from a C ₄ - C ₂₀ α-olefin. It is usually selected from the group consisting of 1-butene, 1-hexene and 1-octene. If the degree of branching of the copolymer of ethylene and α-olefin is too low, the melting point and crystallinity are too high, and it is not suitable for use as a rubber component. If the degree of branching is high, the content of α-olefin is high, which may result in Process difficulty and raw material cost are high, and operability and economy are low. In the prior art, a polyolefin obtained by copolymerizing ethylene with 1-butene or ethylene and 1-octene may be referred to as a polyolefin plastomer or a polyolefin elastomer according to the degree of crystallinity and melting point, and a part of the polyolefin is elastic. Due to its proper crystallinity and melting point, it can be used well with ethylene propylene rubber and has a low degree of branching. It is considered to be an ideal material for improving the aging resistance of ethylene propylene rubber. It can replace ethylene propylene rubber to a certain extent. use. Since the molecular chain of ethylene and 1-octene copolymer is softer, more rubbery and has good physical and mechanical properties relative to the copolymer of ethylene and 1-butene, the polyolefin elastomer commonly used in rubber products is generally ethylene. And the copolymer of 1-octene, the octene weight percentage is generally not higher than 45%, more commonly not higher than 40%, the corresponding degree of branching is generally not higher than 56 branches / 1000 carbon, The more commonly used degree of branching is not higher than 50 branches/1000 carbons, which is much lower than the degree of branching of ethylene dipropylene rubber, so it has excellent aging resistance and good physical and mechanical properties.

The rubber generally needs to be used after cross-linking. In the cross-linking mode commonly used for ethylene-propylene rubber, the copolymer of ethylene and α-olefin may be peroxide cross-linking or irradiation cross-linking, both of which are mainly obtained by capturing tertiary carbon. a hydrogen atom forms a tertiary carbon radical, and then forms a carbon-carbon crosslink by radical bonding, but a copolymer of ethylene and 1-octene (hereinafter referred to as POE) has fewer tertiary carbon atoms and is attached to a tertiary carbon atom. The chain length is large, the steric hindrance is large, and the free radical reaction is difficult to occur, which leads to difficulty in crosslinking, affecting processing efficiency and product performance.

Therefore, there is a need for a better technical solution to improve the aging resistance of ethylene propylene rubber, while having good physical and mechanical properties and cross-linking performance, and it is expected to target specific functional indicators (such as electricity) for rubber products. Insulation performance, etc.) have a good performance.

Summary of the invention:

In view of the problems in the prior art, the present invention provides a rubber-based electrically conductive nonlinear insulating material comprising a novel rubber composition and a processing method thereof, which have a branching degree of not less than 50 branches/1000 carbons. Partial or complete replacement of ethylene-propylene rubber has higher volume resistivity and mechanical strength after cross-linking, and improves the technical defects of ethylene-propylene rubber as a rubber matrix.

In order to achieve the above object, the present invention adopts the following technical solution: a conductive non-linear insulating material comprising a rubber composition comprising a rubber matrix and an essential component, the rubber matrix comprising: by weight: The content of the branched polyethylene a: 0 < a ≤ 100 parts; the content of the binary ethylene propylene rubber and the ethylene propylene diene rubber b: 0 ≤ b < 100 parts; the necessary components in terms of 100 parts by weight of the rubber matrix The method comprises: 1.5 to 8 parts of a crosslinking agent, 10 to 50 parts of a non-linear functional filler, and 5 to 40 parts of a reinforcing filler, wherein the branching degree of the branched polyethylene is not less than 50 branches/1000 carbons. The weight average molecular weight is not less than 50,000, and the Mooney viscosity ML (1+4) is not lower than 2 at 125 °C.

"Branched polyethylene" in the prior art means, in addition to a branched ethylene homopolymer, a branched saturated vinyl copolymer, such as an ethylene-α-olefin copolymer, which may be POE, although POE performs well in physical and mechanical properties and aging resistance, but cross-linking performance is not good, although the branched polyethylene of the present invention can contain both branched ethylene homopolymer and POE, but a better choice It is a branched polyethylene having a high proportion of branched polyethylene or a branched ethylene homopolymer. In a preferred embodiment of the invention, the branched polyethylene contains only branched ethylene homopolymer.

In the further elaboration of the technical solution of the present invention, the branched polyethylene used is a branched ethylene homopolymer unless otherwise specified.

The branched polyethylene used in the present invention is a kind of ethylene homopolymer having a branching degree of not less than 50 branches/1000 carbons, and can be called Branched Polyethylene or Branched PE. Currently, the synthesis method is mainly composed of a late transition metal catalyst. The homopolymerization of ethylene is catalyzed by a "chain walking mechanism", and the preferred late transition metal catalyst may be one of (α-diimine) nickel/palladium catalysts. The nature of the chain walking mechanism refers to the late transition metal catalyst. For example, the (α-diimine) nickel/palladium catalyst is more likely to undergo β-hydrogen elimination reaction and re-insertion reaction in the process of catalyzing olefin polymerization, thereby causing branching. Branched chains of such branched polyethylenes may have different numbers of carbon atoms, specifically 1 to 6, or more carbon atoms.

The production cost of the (α-diimine) nickel catalyst is significantly lower than that of the (α-diimine) palladium catalyst, and the (α-diimine) nickel catalyst catalyzes the high rate of ethylene polymerization and high activity, and is more suitable for industrial applications. Therefore, the branched polyethylene prepared by the ethylene polymerization of the (α-diimine) nickel catalyst is preferred in the present invention.

The degree of branching of the branched polyethylene used in the present invention is preferably 50 to 130 branches/1000 carbons, further preferably 60 to 130 branches/1000 carbons, further preferably 60 to 116 branches/1000. A carbon, the degree of branching between POE and ethylene-propylene rubber, is a new technical solution that is different from the prior art, and can have excellent aging resistance and good cross-linking performance.

Cross-linking performance includes factors such as crosslink density and cross-linking rate, which is the specific performance of the cross-linking ability of the rubber matrix during processing.

The branched polyethylene used in the present invention preferably has a methyl branch content of 40% or more or 50% or more, and has a certain similarity with the structure of the ethylene propylene diene rubber. In terms of cross-linking ability, the degree of branching (tertiary carbon atom content) and the steric hindrance around the tertiary carbon atom are the two main factors affecting the cross-linking ability of the saturated polyolefin. The branched polyethylene used in the present invention is low in degree of branching relative to the ethylene propylene rubber, and since the branched polyethylene has a branch having a carbon number of not less than 2, the branched polycondensation used in the present invention The steric hindrance around the tertiary carbon atom of ethylene is theoretically larger than that of ethylene propylene rubber. It can be judged by combining two factors that the crosslinking ability of the branched polyethylene used in the present invention should be weaker than that of the ethylene propylene rubber. In EPDM rubber. However, the actual cross-linking ability of the partially branched polyethylene used in the present invention is close to that of EPDM rubber, and may even be equal to or better than EPDM rubber. This means that the rubber composition of the present invention can obtain a good aging resistance, can also not weaken the crosslinking ability, and can even have excellent crosslinking performance, which is an unexpected advantageous effect.

This may be explained by the fact that there may be an appropriate number of secondary branched structures on the branched polyethylene used in the preferred embodiment of the present invention, and the so-called secondary branched structure refers to a structure in which branches are further branched. This is also known as "branch-on-branch" during chain walking. Because of the low steric hindrance around the tertiary carbon atoms of the secondary branches, cross-linking reactions are more likely to occur. Having a secondary branched structure is a distinct distinction between the branched polyethylene used in the preferred embodiment of the invention and the prior art ethylene dipropylene rubber or the conventional ethylene-α-olefin copolymer.

It is a new technical solution to improve the cross-linking ability of saturated polyolefin elastomer by using the secondary steric structure with lower steric hindrance. Under the technical solution of the present invention, it is also considered to be within the technical protection of the present invention to include a vinyl copolymer having a secondary branched structure or other saturated hydrocarbon polymer in the rubber matrix. The vinyl copolymer refers to a copolymer of ethylene and a branched α-olefin, and has a secondary branched structure, wherein the branched α-olefin may be selected from the group consisting of isobutylene and 3-methyl-1- Butylene, 4-methyl-1-pentene, 3-methyl-1-pentene, 2-methyl-1-heptene, 3-methyl-1-heptene, 4-methyl-1- The heptene, 5-methyl-1-heptene, 6-methyl-1-heptene, and the like, the comonomer may also contain a common linear alpha-olefin.

It is generally believed in the prior art that the branched polyethylene prepared by the (α-diimine) nickel catalyst is difficult to exist in the secondary branched structure, and at least it is difficult to sufficiently distinguish it. The technical solution of the present invention is also to analyze the branched polycondensation. The structure of ethylene provides a new idea.

Compared with ethylene propylene rubber, when the branched polyethylene has an appropriate number of secondary branched structures, the cross-linking point of the branched polyethylene can be generated on the tertiary chain of the main chain during the peroxide crosslinking process. It can also be produced on the branched tertiary carbon of the secondary structure, so the rubber network formed by the cross-linking of the branched polyethylene has a richer CC connecting segment between the main chains than the ethylene-propylene rubber. The length can effectively avoid stress concentration and help to obtain better mechanical properties.

A further technical solution is that, in 100 parts by weight, the content of branched polyethylene in the rubber matrix is a: 10 ≤ a ≤ 100 parts; the content of binary ethylene propylene rubber and ethylene propylene diene rubber is b: 0 ≤ b ≤90 parts; the branched polyethylene is an ethylene homopolymer with a degree of branching of 60-130 branches/1000 carbons, a weight average molecular weight of 66,000 to 518,000, and a Mooney viscosity ML (1+4) ) 125 ° C is 6 ~ 102;

A further technical solution is that the content of the branched polyethylene in the 100 parts by weight of the rubber matrix is a: 10 ≤ a ≤ 100 parts; the content of the binary ethylene propylene rubber and the EPDM rubber is b: 0 ≤ b ≤ 90 parts The branched polyethylene is an ethylene homopolymer having a degree of branching of 70-116 branches/1000 carbons, a weight average molecular weight of 201,000 to 436,000, and a Mooney viscosity of ML (1+4) 125 ° C. 23 to 101;

A further technical solution is that the content of the branched polyethylene in the 100 parts by weight of the rubber matrix is a: 10 ≤ a ≤ 100 parts; the content of the binary ethylene propylene rubber and the EPDM rubber is b: 0 ≤ b ≤ 90 parts The branched polyethylene is an ethylene homopolymer having a degree of branching of 80-105 branches/1000 carbons, a weight average molecular weight of 250,000 to 400,000, and a Mooney viscosity of ML (1+4) 125 ° C. It is 40 to 95.

A further technical solution is that the content of the branched polyethylene in the 100 parts by weight of the rubber matrix is a: 10 ≤ a ≤ 100 parts; the content of the binary ethylene propylene rubber and the EPDM rubber is b: 0 ≤ b ≤ 90 parts The branched polyethylene is an ethylene homopolymer having a degree of branching of 80-105 branches/1000 carbons, a weight average molecular weight of 268,000 to 356,000, and a Mooney viscosity of ML (1+4) 125 ° C. It is 42 to 80.

A further technical solution is that the third monomer of the ethylene propylene diene monomer is preferably a diene monomer, specifically selected from the group consisting of 5-ethylidene-2-norbornene and 5-vinyl-2-nor Borneene, 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-pentylene-2-nor Borbornene, 1,5-cyclooctadiene, 1,4-cyclooctadiene, and the like. Specifically, the ethylene propylene rubber may contain two or more kinds of diene monomers at the same time, such as 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene. The functional group of the diene monomer can function as an intrinsic co-crosslinking agent in the vulcanization of the peroxide to improve the crosslinking efficiency. This helps to reduce the amount and residual amount of crosslinker and co-crosslinker required and the cost of adding them. The weight specific gravity of the diene monomer to the ethylene propylene rubber is preferably from 1% to 14%, more preferably from 3% to 10%, still more preferably from 4% to 7%.

A further technical solution is characterized in that the crosslinking agent comprises at least one of a peroxide crosslinking agent and a sulfur, and the peroxide crosslinking agent comprises di-tert-butyl peroxide and 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 At least one of 5-dimethyl-2,5-bis(benzoyl peroxy)hexane, tert-butyl peroxybenzoate, and t-butylperoxy-2-ethylhexyl carbonate.

A further technical solution is that the content of the non-linear functional filler is from 12 to 20 parts based on 100 parts by weight of the rubber matrix.

In a further technical solution, the non-linear functional filler comprises at least one of nano zinc oxide, nano titanium dioxide, nano silicon carbide, carbon nanotube, conductive carbon black and nano graphite.

In a further technical solution, the reinforcing filler comprises at least one of fumed silica, calcium carbonate, talc, and carbon black.

A further technical solution is that the reinforcing filler is contained in an amount of 10 to 30 parts by weight based on 100 parts by weight of the rubber base.

A further technical solution is that the electrically conductive non-linear insulating material further comprises an auxiliary component, which is based on 100 parts by weight of the rubber matrix, and the auxiliary component comprises: a co-crosslinking agent: 0.2 to 5 parts, plasticized 2 to 15 parts of the agent, 0.5 to 2 parts of the stabilizer, and 0 to 3 parts of the vulcanization accelerator.

A further technical solution is that the co-crosslinking agent comprises triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, Triallyl trimellitate, trimethylolpropane trimethacrylate, N,N'-m-phenylene bismaleimide, N,N'-bis-indenylacetone, 1,2- At least one of polybutadiene, dibenzoyl p-nonane, a metal salt of an unsaturated carboxylic acid, and sulfur. The unsaturated carboxylic acid metal salt contains at least one of zinc acrylate, zinc methacrylate, magnesium methacrylate, calcium methacrylate, and aluminum methacrylate.

In a further technical solution, the plasticizer comprises at least one of paraffin oil, naphthenic oil, transformer oil, paraffin wax, and stearic acid.

In a further technical solution, the stabilizer comprises 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6-ethoxy-2,2,4-trimethyl At least one of -1,2-dihydroquinoline (AW) and 2-mercaptobenzimidazole (MB).

According to a further technical proposal, the vulcanization accelerator comprises 2-thiol benzothiazole, dibenzothiazyl disulfide, tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, tetrazyl disulfide Kethiram, N-cyclohexyl-2-benzothiazolyl sulfenamide, N,N-dicyclohexyl-2-benzothiazolyl sulfenamide, bismaleimide, ethylene thiourea At least one of them.

According to a further technical solution, the particle size of the fumed silica is 20 nm to 80 nm, the particle size of the nano zinc oxide is 20 nm to 50 nm, the particle diameter of the nano titanium dioxide is 40 nm to 60 nm, and the particle size of the nano silicon carbide is 30 nm. ～60 nm, the carbon nanotubes are single-walled carbon nanotubes having a diameter of 5 nm to 10 nm and a tube length of 5 μm to 15 μm. The conductive carbon black has a particle diameter of 20 nm to 40 nm, and the nanographite has a sheet thickness of 40 nm to 60 nm and a sheet diameter of 1 μm. 2 μm.

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. Vulcanized rubber can also be referred to simply as vulcanizate.

Compared with the prior art, the beneficial effects of the invention are: the branched polyethylene used does not contain the third monomer of the diene, so the electrical insulation performance is similar to that of the EPM, which is superior to the EPDM, but is also carried out due to the relative EPM. The cross-linking reaction has high cross-linking efficiency and mechanical strength. When the rubber matrix contains branched polyethylene, the new rubber composition can effectively improve the high electrical insulation and mechanical strength in the prior art. The problem can be better applied to the conductance nonlinear insulation material.

detailed description

The following examples are given to further illustrate the present invention, but are not intended to limit the scope of the present invention, and some non-essential improvements and adjustments made by those skilled in the art based on the present invention remain within the scope of the present invention. .

In order to more clearly describe the embodiments of the present invention, the materials to which the present invention relates are defined below.

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

The Mooney viscosity ML (1+4) of the ethylene propylene diene rubber used is preferably 20 to 100, more preferably 40 to 60, preferably ethylene, 50% to 75%, and the third monomer is 5-ethylene. 2-norbornene, 5-vinyl-2-norbornene or dicyclopentadiene, the third monomer content being from 1% to 7%.

The branched polyethylene used can be obtained by catalyzing the homopolymerization of ethylene by a (α-diimine) nickel catalyst under the action of a cocatalyst. The structure, synthesis method and method for preparing branched polyethylene by using the (α-diimine) nickel catalyst are disclosed in the prior art, and can be used but are not limited to the following documents: CN102827312A, CN101812145A, CN101531725A, CN104926962A, US6103658, US6660677.

The selected branched polyethylene is characterized by a branching degree of 60 to 130 branches/1000 carbons, a weight average molecular weight of 66,000 to 518,000, and a Mooney viscosity of ML (1+4) of 125 ° C of 6 to 102. . Among them, the degree of branching is measured by nuclear magnetic resonance spectroscopy, and the molar percentages of various branches are measured by nuclear magnetic carbon spectroscopy.

Rubber performance test method:

1. Tensile strength and elongation at break performance test: According to the national standard GB/T528-2009, the test is carried out with an electronic tensile tester, the tensile speed is 500mm/min, the test temperature is 23±2°C, and the sample is type 2 Dumbbell sample

2. Conductivity and nonlinear coefficient test: Place the sample to be tested in an oven and place a three-electrode system in the box. Heat the oven to the specified temperature for more than 2 hours, so that the sample is fully preheated to reduce measurement error. Each time 4 identical samples are measured and averaged, measured every 10 minutes and recorded, and then the electric current flow under the next electric field strength is tested. The voltage adjustment range is 0V-10000V, according to the change of conductivity and field strength. The relationship yields a nonlinear coefficient;

3, volume resistivity test: in accordance with the national standard GB/T1692-2008, using a high resistance meter for testing;

4, DC breakdown strength test: DC high-voltage generator, the boost range is 0-60kV. A cylindrical electrode is used, and the diameter of the high-voltage pole is 25 mm. The sample and the electrode are all immersed in the transformer oil to prevent surface air breakdown. The step-up speed is about 1kV/s, and the voltage is continuously increased until the sample is broken down, and the thickness of the sample and the voltage value at the time of breakdown are recorded;

5, the positive curing time Tc90 test: in accordance with the national standard GB/T16584-1996, in the rotorless vulcanizer, the test temperature is 170 °C.

The vulcanization conditions of all the following examples were uniform: temperature: 170 ° C; pressure: 16 MPa; time was Tc90 + 2 min.

Example 1:

The branched polyethylene used was numbered PER-8.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed is 50 rpm, add 80 parts of ethylene propylene diene rubber and 20 parts of branched polyethylene for 90 seconds, and add 15 parts of gas phase. Method white carbon black, 12 parts of nano zinc oxide, 1 part of nano titanium dioxide, 4 parts of nano silicon carbide, 1 part of carbon nanotubes, 0.5 part of conductive carbon black, 0.5 part of nanographite, kneaded for 20 minutes; finally added 2.6 parts of cross-linking Dicumyl peroxide (DCP), 0.6 parts of cross-linking agent dibenzoyl palladium and 0.3 parts of sulfur, after 5 minutes of mixing, the rubber is discharged, and the mixture is opened at a roll temperature of 60 ° C. Thin on the refiner, a sheet with a thickness of about 2.5 mm, and parked for 20 hours.

(2) After pressure vulcanization on a flat vulcanizing machine, a non-conductive non-linear material was obtained, and each test was carried out after being parked for 16 hours.

Example 2:

The branched polyethylene used was numbered PER-5.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed to 50 rpm, add 30 parts of EPDM rubber and 70 parts of branched polyethylene for 90 seconds premixing; add 10 parts of gas phase Method white carbon black, 12 parts of nano zinc oxide, 1 part of nano titanium dioxide, 4 parts of nano silicon carbide, 1 part of carbon nanotubes, 0.5 part of conductive carbon black, 0.5 part of nanographite, kneaded for 20 minutes; finally added 2.6 parts of cross-linking Dicumyl peroxide (DCP), 0.6 parts of cross-linking agent dibenzoyl palladium and 0.3 parts of sulfur, after 5 minutes of mixing, the rubber is discharged, and the mixture is opened at a roll temperature of 60 ° C. Thin on the refiner, a sheet with a thickness of about 2.5 mm, and parked for 20 hours.

Example 3:

The branched polyethylene used was numbered PER-4.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed to 50 rpm, add 100 parts of branched polyethylene pre-pressed and kneaded for 90 seconds; add 15 parts of fumed silica, 12 parts of nano Zinc oxide, 1 part of nano titanium dioxide, 4 parts of nano silicon carbide, 1 part of carbon nanotubes, 0.5 part of conductive carbon black, 0.5 part of nanographite, kneaded for 20 minutes; finally added 2.6 parts of crosslinker dicumyl peroxide ( DCP), 0.6 parts of the cross-linking agent dibenzoyl p-quinone and 0.3 parts of sulfur were mixed for 5 minutes and then discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left to stand for 20 hours.

Comparative Example 1:

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed is 50 rpm, add 100 parts of EPDM rubber for 90 seconds, and add 15 parts of fumed silica, 12 parts. Nano zinc oxide, 1 part nano titanium dioxide, 4 parts nano silicon carbide, 1 part carbon nanotube, 0.5 part conductive carbon black, 0.5 part nano graphite, kneaded for 20 minutes; finally added 2.6 parts crosslinker dicumyl peroxide (DCP), 0.6 parts of the cross-linking agent dibenzoyl p-quinone and 0.3 parts of sulfur, and the mixture was kneaded for 5 minutes and then discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left to stand for 20 hours.

The performance test data of Examples 1-3 and Comparative Example 1 are as follows:

Example 4:

The branched polyethylene used was numbered PER-9.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed to 50 rpm, add 90 parts of EPDM rubber and 10 parts of branched polyethylene for 90 seconds; add 1 part of anti-aging Agent RD, 1 part stearic acid, 20 parts fumed silica, 8 parts nano zinc oxide, 2 parts nano titanium dioxide, 6 parts nano silicon carbide, 1 part carbon nanotube, 1 part conductive carbon black, 0.5 part nano graphite And 3 parts of paraffin oil SUNPAR2280, mixing for 20 minutes; finally adding 3 parts of cross-linking agent dicumyl peroxide (DCP), 0.5 parts of cross-linking agent dibenzoyl p-terpene and 0.3 parts of sulfur, mixing Discharge the glue after 5 minutes. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left to stand for 20 hours.

Example 5:

The branched polyethylene used was numbered PER-7.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed is 50 rpm, add 20 parts of ethylene propylene rubber, 50 parts of ethylene propylene diene monomer and 30 parts of branched polyethylene pre-pressure mixing. 90 seconds; add 2 parts of stearic acid, 20 parts of fumed silica, 20 parts of nano zinc oxide, 3 parts of nano titanium dioxide, 10 parts of nano silicon carbide, 3 parts of carbon nanotubes, 1 part of conductive carbon black, 1 part Nano-graphite and 5 parts of paraffin oil SUNPAR2280, mixing for 20 minutes; finally adding 5 parts of cross-linking agent dicumyl peroxide (DCP), mixing for 5 minutes, then discharging the glue, the mixture is at a roll temperature of 60 ° C The thin open on the open mill, the sheet with a thickness of about 2.5mm, and parked for 20 hours.

Example 6

The branched polyethylene used was numbered PER-6.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed is 50 rpm, add 20 parts of ethylene propylene diene rubber, 30 parts of ethylene propylene diene monomer and 50 parts of prepolymerized polyethylene. 90 seconds; add 2 parts of stearic acid, 5 parts of fumed silica, 30 parts of nano zinc oxide, 4 parts of nano titanium dioxide, 12 parts of nano silicon carbide, 2 parts of carbon nanotubes, 1 part of conductive carbon black, 1 part Nano-graphite and 10 parts of paraffin oil SUNPAR2280, mixed for 20 minutes; finally added 8 parts of cross-linking agent dicumyl peroxide (DCP), 3 parts of cross-linking agent triallyl isocyanurate (TAIC) and 1.5 parts of co-crosslinking agent dibenzoyl palladium oxime, after 5 minutes of mixing, the rubber is discharged, and the rubber compound is thinly passed on an open mill with a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and parked 20 hour.

Example 7

The branched polyethylene used was numbered PER-5.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed to 50 rpm, add 50 parts of ethylene propylene diene rubber and 50 parts of branched polyethylene for 90 seconds; add 2 parts of hard Fatty acid, 20 parts of fumed silica, 20 parts of nano-zinc oxide, 4 parts of nano-titanium dioxide, 8 parts of nano-silicon carbide, 1 part of carbon nanotubes, 1 part of conductive carbon black, 1 part of nano-graphite and 10 parts of paraffin oil SUNPAR2280 , mixing for 20 minutes; finally adding 5 parts of cross-linking agent dicumyl peroxide (DCP) and 0.5 parts of dibenzothiazyl disulfide (DM), mixing for 5 minutes, then discharging the glue, mixing the mixture at the roll temperature It was thin on the 60 ° C open mill, and a sheet having a thickness of about 2.5 mm was obtained and parked for 20 hours.

Example 8

The branched polyethylene used was numbered PER-3.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed is 50 rpm, add 100 parts of branched polyethylene pre-pressed and kneaded for 90 seconds; add 1 part of antioxidant RD, 1 part of stearic acid 30 parts of fumed silica, 8 parts of nano zinc oxide, 2 parts of nano titanium dioxide, 6 parts of nano silicon carbide, 1 part of carbon nanotubes, 1 part of conductive carbon black, 0.5 part of nano graphite and 2 parts of paraffin oil SUNPAR 2280, mixed Refining for 20 minutes; finally adding 3 parts of cross-linking agent dicumyl peroxide (DCP), 1 part of cross-linking agent dibenzoyl p-terpene and 0.3 parts of sulfur, mixing for 5 minutes, then discharging the glue, mixing The rubber was thinly passed on an open mill with a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm and parked for 20 hours.

Example 9

The branched polyethylenes used were numbered PER-1 and PER-7.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed to 50 rpm, add 20 parts of PER-1 and 80 parts of PER-7 pre-pressure mixing for 90 seconds; add 1 part of antioxidant RD, 1 part stearic acid, 40 parts of fumed silica, 4 parts of nano zinc oxide, 1 part of nano titanium dioxide, 3 parts of nano silicon carbide, 1 part of carbon nanotubes, 0.5 part of conductive carbon black, 0.5 part of nano graphite, mixing 20 minutes; finally add 1 part of cross-linking agent dicumyl peroxide (DCP), 0.5 part of cross-linking agent dibenzoyl p-terpene, 0.5 part of cross-linking sulfur and 1 part of dibenzothiazole disulfide (DM), after 5 minutes of kneading, the rubber was discharged, and the kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left to stand for 20 hours.

(2) After pressure vulcanization on a flat vulcanizing machine, a non-conductive non-linear material was obtained, and after each 16 hours of parking, various tests were performed.

Example 10:

The branched polyethylenes used were numbered PER-2 and PER-6.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed to 50 rpm, add 30 parts of PER-2 and 70 parts of PER-6 pre-pressure mixing for 90 seconds; add 1 part of antioxidant RD, 20 parts of fumed silica, 12 parts of nano zinc oxide, 2 parts of nano titanium dioxide, 4 parts of nano silicon carbide, 1 part of carbon nanotubes, 0.5 parts of conductive carbon black, 0.5 parts of nanographite and 2 parts of paraffin oil SUNPAR 2280, mixed 20 minutes; finally, add 3 parts of cross-linking agent dicumyl peroxide (DCP), 1 part of cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur, and mix for 5 minutes. . The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left to stand for 20 hours.

The performance test data of Examples 4 to 10 are as follows:

Example 11

The branched polyethylene used was numbered PER-11.

The processing steps are as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed is 50 rpm, add 100 parts of PER-11 pre-pressing and kneading for 90 seconds; add 1 part of antioxidant RD, 20 parts of fumed white carbon Black, 10 parts of nano zinc oxide, 2 parts of nano titanium dioxide, 4 parts of nano silicon carbide, 1 part of carbon nanotubes, 0.5 parts of conductive carbon black, 0.5 parts of nanographite and 2 parts of paraffin oil SUNPAR 2280, mixed for 20 minutes; finally added 3 The cross-linking agent dicumyl peroxide (DCP), 1 part of the cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur were mixed for 5 minutes and then discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left to stand for 20 hours.

Example 12

The branched polyethylene used was PER-12, and the remaining formulation components and processing techniques were in accordance with Example 11.

Example 13

The branched polyethylene used was 40 parts PER-12 and 60 parts PER-10, and the remaining formulation components and processing techniques were in accordance with Example 11.

The performance test data of Examples 11 to 13 are as follows:

Claims

An electrically conductive non-linear insulating material, characterized in that the electrically conductive non-linear insulating material comprises a rubber composition comprising: a rubber matrix and an essential component, the rubber matrix comprising: a branch in parts by weight The content of the polyethylene is a: 0 < a ≤ 100 parts; the content of the binary ethylene propylene rubber and the ethylene propylene diene rubber b: 0 ≤ b < 100 parts;

The essential component comprises: 1.5 to 8 parts of a crosslinking agent, 10 to 50 parts of a non-linear functional filler, and 5 to 40 parts of a reinforcing filler, wherein the branched polyethylene comprises ethylene, based on 100 parts by weight of the rubber matrix. The homopolymer has a branching degree of not less than 50 branches/1000 carbons, a weight average molecular weight of not less than 50,000, and a Mooney viscosity of ML (1+4) of not lower than 2 at 125 °C.
The electrically conductive non-linear insulating material according to claim 1, wherein the content of the branched polyethylene in the rubber matrix is 100% by weight: 10 ≤ a ≤ 100 parts; the binary ethylene propylene rubber and the ternary The content of ethylene propylene rubber b: 0 ≤ b ≤ 90 parts; the branched polyethylene is an ethylene homopolymer, the degree of branching is 60-130 branches / 1000 carbon, and the weight average molecular weight is 66,000 ~ 51.8 Million, Mooney viscosity ML (1 + 4) 125 ° C is 6 ~ 102;
The electrically conductive nonlinear insulating material 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 two uncles. 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-butyl) Isopropyl benzoate, 2,5-dimethyl-2,5-bis(benzoyl peroxy)hexane, tert-butyl peroxybenzoate, tert-butylperoxy-2-ethylhexyl At least one of carbonates.
The electrically conductive non-linear insulating material according to claim 1, wherein the non-linear functional filler is contained in an amount of from 12 to 20 parts based on 100 parts by weight of the rubber base.
The electrically conductive nonlinear insulating material according to claim 1, wherein the non-linear functional filler comprises at least at least one of nano zinc oxide, nano titanium dioxide, nano silicon carbide, carbon nanotube, conductive carbon black and nano graphite. A nano zinc oxide having a particle diameter of 20 nm to 50 nm, a nano titanium dioxide having a particle diameter of 40 nm to 60 nm, a nano silicon carbide having a particle diameter of 30 nm to 60 nm, and a carbon nanotube having a diameter of 5 nm to 10 nm and a tube length of 5 μm to 15 μm. The single-walled carbon nanotubes have a particle diameter of 20 nm to 40 nm, the nanographite has a sheet thickness of 40 nm to 60 nm, and a sheet diameter of 1 μm to 2 μm.
The electrically conductive non-linear insulating material according to claim 1, wherein the reinforcing filler comprises at least one of fumed silica, calcium carbonate, talc, and carbon black. The silica has a particle diameter of 20 nm to 80 nm.
The electrically conductive non-linear insulating material according to claim 1, wherein the rubber composition in the electrically conductive non-linear insulating material further comprises an auxiliary component, wherein the auxiliary component is based on 100 parts by weight of the rubber base. The dosage comprises: a co-crosslinking agent: 0.2 to 5 parts, a plasticizer 2 to 15 parts, a stabilizer 0.5 to 2 parts, and a vulcanization accelerator 0 to 3 parts.
The electrically conductive non-linear insulating material according to claim 7, wherein the co-crosslinking agent comprises triallyl cyanurate, triallyl isocyanurate, ethylene glycol Acrylate, triethylene glycol dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, N,N'-m-phenylene bismaleimide, N, At least one of N'-bis-indenyl acetonone, 1,2-polybutadiene, dibenzoyl p-nonane, a metal salt of an unsaturated carboxylic acid, and sulfur.
The electrically conductive nonlinear insulating material according to claim 7, wherein the plasticizer comprises at least one of paraffin oil, naphthenic oil, transformer oil, paraffin wax, and stearic acid.
The electrically conductive nonlinear insulating material according to claim 7, wherein said stabilizer comprises 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6- At least one of ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (AW) and 2-mercaptobenzimidazole (MB).
The electrically conductive non-linear insulating material according to claim 7, wherein the vulcanization accelerator comprises 2-thiol benzothiazole, dibenzothiazyl disulfide, tetramethylthiuram monosulfide, Tetramethylthiuram disulfide, tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolyl sulfenamide, N,N-dicyclohexyl-2-phenylthiazolyl sulfenamide, At least one of bismaleimide and ethylene thiourea.
A method of producing the electrically conductive non-linear insulating material according to any one of claims 1 to 11, characterized in that the production method comprises the following steps:

(1) Rubber mixing: set the temperature of the internal mixer and the rotor speed, add the rubber matrix pre-compression mixing; add anti-aging agent, plasticizer, reinforcing filler and non-linear functional filler, mix; finally add cross-linking system After the mixing, the rubber is drained, and the rubber compound is thinly passed through the open mill at a roll temperature of 60 ° C to obtain a sheet, which is parked. The crosslinking system contains a crosslinking agent, and may further comprise a crosslinking agent and a vulcanization accelerator. At least one of them;

(2) A conductive non-linear material is obtained after press vulcanization on a flat vulcanizer.