WO2020011002A1

WO2020011002A1 - Rubber composition, processing method therefor, rubber product using rubber composition, and production method therefor

Info

Publication number: WO2020011002A1
Application number: PCT/CN2019/092641
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: 2018-07-13
Filing date: 2019-06-25
Publication date: 2020-01-16
Also published as: CN110713658B; CN110713658A

Abstract

The present invention relates to a rubber composition, a processing method therefor, and a product using the rubber composition, and a production method therefor. The rubber composition comprises a rubber substrate, a reinforcing filler and a crosslinking agent. The rubber substrate contains for 100 parts in weight: 1-99 parts of branched polyethylene, 0-90 parts of ethylene propylene rubber, and 1-95 parts of isoprene elastomer. Advantages of the rubber composition include good aging resistance, good physical mechanical properties and good compression set resistance. The rubber composition can be used for producing rubber products, such as rubber bearings, tires, rubber hoses, conveying belts and the like.

Description

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

Technical field

The present invention belongs to the field of rubber, and particularly relates to a rubber composition and a processing method thereof. The present invention also relates to the application of the rubber composition and a method for producing the rubber product.

Background technique

Isoprene-based elastomers mainly include natural rubber and synthetic isoprene rubber, which occupy the highest consumption proportion in the overall rubber raw materials. Especially natural rubber, because of its high output, and has excellent mechanical properties, resilience, flex resistance, wear resistance, adhesion, etc., is widely used in tires, hoses, tapes, rubber rollers, sole materials, In gloves, rubber parts and other rubber products. However, although natural rubber has many of the above excellent properties, due to its high degree of unsaturation, its products have poor aging resistance.

Ethylene-propylene rubber, due to its highly saturated molecular structure, has excellent aging resistance, and is widely used in places where aging resistance is required. However, due to poor adhesive properties and relatively weak mechanical properties, its application fields are also limited. limits.

In the prior art, the advantages of the two are often complemented by the combined use of ethylene-propylene rubber and natural rubber. However, due to the poor co-vulcanization properties of the two, the physical and mechanical strength of ethylene-propylene rubber is lower than that of natural rubber, and the use of ethylene-propylene rubber will reduce the physical and mechanical properties while improving the aging resistance. In the prior art, there have been sufficient studies to improve the co-vulcanization performance of ethylene-propylene rubber and natural rubber, and a composite vulcanization system shared by sulfur and peroxide can already achieve a relatively good co-vulcanization degree. However, the relatively poor physical and mechanical properties of ethylene-propylene rubber in peroxide-based vulcanization systems have not been significantly improved. Therefore, there is still a need and room for further improvement in the physical and mechanical properties of rubber products that are used in combination.

Therefore, for applications that require high physical and mechanical properties, in order not to affect the use effect and reduce costs, often only a small amount of ethylene-propylene rubber can be used in combination, and the aging resistance of the product cannot be further improved. On the other hand, in the case of high requirements for aging resistance, in order not to affect the use effect, often only a small amount of natural rubber can be used in combination, and the physical mechanical properties and adhesive properties of the rubber cannot be further improved.

Summary of the invention

In view of the shortcomings in the prior art, the object of the present invention is to provide a new rubber composition that is more excellent in comprehensive performance in terms of aging resistance and physical and mechanical properties.

In order to achieve the above object, the technical solution proposed by the present invention is to use a branched polyethylene to partially or completely replace the ethylene-propylene rubber in the prior art and to use it together with an isoprene-based elastomer. The branched polyethylene used in the present invention is a type of ethylene homopolymer with a degree of branching of not less than 50 branches / 1000 carbons. At present, its synthesis method mainly uses (α-diimide) nickel / palladium catalyst through compounding In situ polymerization catalyzes homopolymerization of ethylene.

Because the molecular weight of branched polyethylene is completely saturated, it is suitable for peroxide vulcanization systems, and its aging resistance is similar to or better than ethylene-propylene rubber. At the same time, because the branched polyethylene has a rich branching distribution, compared to ethylene-propylene rubber whose branching is mainly methyl, the regularity of the molecular chain can be destroyed to a greater extent. At the same molecular weight, it has a lower Mooney viscosity and better processing performance, and it is easier to form a continuous phase when used with other rubber grades such as natural rubber at the same amount, so that the overall has better aging resistance; on the other hand, at the same Mooney viscosity In the following, branched polyethylene can have a higher molecular weight, and branch chains of different lengths of branched polyethylene can form a variety of CC crosslinks of different lengths between the molecular main chains during peroxide vulcanization, effectively avoiding Stress concentration, which gives the overall higher physical and mechanical properties. Therefore, the present invention can provide a rubber composition having both good aging resistance and physical and mechanical properties.

In order to achieve the above object, the technical solution adopted by the present invention relates to a rubber composition including a rubber matrix, a reinforcing filler, and a cross-linking agent. In terms of parts by weight, each 100 parts of the rubber matrix contains more than 0 parts and Not more than 99 parts of branched polyethylene, 0 to 90 parts of ethylene-propylene rubber and 1 to 95 parts of isoprene-based elastomers, wherein the branched polyethylene is an ethylene homopolymer having a branched structure.

A further technical solution is that the said rubber matrix contains 5 to 95 parts of branched polyethylene per 100 parts by weight.

A further technical solution is that the degree of branching of the branched polyethylene is 50 to 150 branches / 1000 carbons.

A further technical solution is that the degree of branching of the branched polyethylene is 60 to 130 branches / 1000 carbons.

A further technical solution is that the weight average molecular weight of the branched polyethylene is 66,000 to 518,000, and the Mooney viscosity ML (1 + 4) is 6 to 102 at 125 ° C.

Branched polyethylene with a lower degree of branching has a higher molecular weight and Mooney viscosity, and even has a melting point above room temperature. The addition of such branched polyethylene in a combined system can give the overall good aging resistance and wear resistance. Properties, increase rubber stiffness and improve process performance.

Branched polyethylene with a higher degree of branching has a lower molecular weight and Mooney viscosity, which can be used to improve the processing properties of ethylene-propylene rubber or branched polyethylene with a slightly lower degree of branching, and make the latter easier to form continuous Phase, so that in the case of a higher specific gravity of natural rubber, it gives better overall aging resistance.

A further technical solution is that the ethylene-propylene rubber includes at least one of ethylene-propylene rubber, ethylene-propylene rubber and ethylene-propylene rubber.

A further technical solution is that, in addition to ethylene and propylene, the comonomers of the EPDM rubber and the EPDM rubber include diene monomers, and the diene monomers include 5-ethylene- At least one of 2-norbornene, 5-vinyl-2-norbornene, dicyclopentadiene, and 1,4-hexadiene. Examples of the diene monomer that can be used include 1,5-hexadiene, 1,4-pentadiene, 2-methyl-1,4-pentadiene, 3-methyl-1,4 -Hexadiene, 4-methyl-1,4-hexadiene, 1,9-decadiene, 5methylene-2-norbornene, 5-pentyl-2-norbornene, 1 , 5-cyclooctadiene, 1,4-cyclooctadiene, etc.

A further technical solution is that the weight ratio of the diene monomer to the ethylene-propylene rubber is 1% to 14%.

The ethylene-propylene rubber used is preferably a tertiary or quaternary ethylene-propylene rubber having a Mooney viscosity ML (1 + 4) of 125 to 125 ° C and a weight ratio of diene monomer of 4% to 10%. The compatibility of the polyethylene is very good. When mixing, the masterbatch method is generally used. Ethylene-propylene rubber and branched polyethylene are a kind of rubber matrix for the masterbatch. When the monomer content is high, the polarity of the masterbatch can be increased, and it can help the uniform dispersion of various fillers in the final rubber. At the same time, the third monomer can also act as a peroxide crosslinker. To improve the efficiency of cross-linking. The molecular chain of EPDM rubber can either co-crosslink sulfur and peroxide with the molecular chain of natural rubber, or co-crosslink with peroxide between branched polyethylene, thereby increasing the rubber phase. The distribution of cross-linking bonds at the interface can further improve the overall co-vulcanizability and physical and mechanical properties, especially when ethylene-propylene rubber contains both 5-ethylene-2-norbornene (ENB) and 5-vinyl -2- When norbornene (VNB) is a diene monomer, or when EPB with ENB and VNB as the third monomer is used together, ENB easily reacts with sulfur, while VNB generally only reacts with peroxide. Cross-linking agent reaction, so such ethylene-propylene rubber (combination) can better play the role of co-vulcanizing agent.

A further technical solution is that the isoprene-based elastomer includes at least one of natural rubber, synthetic polyisoprene, and an isoprene copolymer.

A further technical solution is that the isoprene copolymer comprises a butadiene-isoprene copolymer, an isoprene-styrene copolymer, and a butadiene-isoprene-styrene copolymer. At least one.

A further technical solution is that the isoprene-based elastomer is preferably a natural rubber.

A further technical solution is that, based on 100 parts by weight of the rubber matrix, the rubber composition includes 10 to 200 parts of a reinforcing filler.

A further technical solution is characterized in that the reinforcing filler comprises carbon black, white carbon black, calcium carbonate, calcined clay, talc, magnesium silicate, aluminum silicate, magnesium carbonate, titanium dioxide, montmorillonite And at least one of short fibers.

The white carbon black is preferably white carbon black pretreated with alkylation, which is beneficial for improving the dispersion effect of the white carbon black in the rubber matrix of the present invention and improving the physical properties of the rubber. Montmorillonite is preferably modified montmorillonite or nano-montmorillonite. Adding nano-layered montmorillonite is beneficial to improve the mechanical properties and wear resistance of vulcanizate.

A further technical solution is that, based on 100 parts by weight of the rubber matrix, the rubber composition includes 0.1 to 10 parts of a crosslinking agent.

A further technical solution is that the crosslinking agent comprises at least one of a peroxide crosslinking agent and sulfur, and the peroxide crosslinking agent is di-t-butyl peroxide, dicumyl peroxide, Tert-butylcumyl 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-butylperoxy-3-hexyne, bis (tert-butylisopropylperoxy) benzene (BIPB), 2 At least one of 2,5-dimethyl-2,5-di (benzoic acid peroxy) hexane, tert-butyl peroxybenzoate, and tert-butyl peroxy-2-ethylhexyl carbonate.

Because the scorch time of peroxide vulcanization is generally shorter than sulfur vulcanization, if the product production process requires extended scorch time, extended scorch organic peroxide F40P-SP2 can be used, or BHT can be added and the amount of peroxide can be appropriately increased. Or, add a cross-linking agent such as N, N'-m-phenylene bismaleimide, which has the effect of extending the scorch time.

A further technical solution is that the above rubber composition, based on parts by weight, contains 10 to 95 parts of branched polyethylene, 0 to 60 parts of ethylene-propylene rubber and 5 to 90 parts of natural rubber per 100 parts of the rubber matrix; The rubber composition includes 15 to 150 parts of a reinforcing filler and 1 to 8 parts of a crosslinking agent based on parts by weight of the rubber matrix.

A further technical solution is that the rubber composition further includes an auxiliary component. The auxiliary components include a cross-linking aid, a plasticizer, a metal oxide, stearic acid, a surface modifier, a stabilizer, a vulcanization accelerator, a compatibilizer, a tackifier, an adhesive, and a flame retardant. At least one of foaming agents.

A further technical solution is that, based on 100 parts by weight of the rubber matrix, the amount of the various auxiliary components used ranges from 0.2 to 10 parts of a cross-linking aid, 0 to 80 parts of a plasticizer, 3 to 30 parts of a metal oxide, and stearin. 0 to 3 parts of acid, 0 to 15 parts of surface modifier, 1 to 6 parts of stabilizer, 0 to 5 parts of vulcanization accelerator, 0 to 15 parts of compatibilizer, 0 to 5 parts of tackifier, 0 -20 parts, flame retardant 0 to 150 parts, foaming agent 0 to 20 parts.

A further technical solution is that the aforesaid co-crosslinking agent includes triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, triethylene dimethacrylate, Triallyl trimellitate, trimethylolpropane trimethacrylate, N, N'-m-phenylenebismaleimide, N, N'-bisfurfurylacetone, 1,2-poly At least one of butadiene, unsaturated carboxylic acid metal salt, and sulfur.

The above-mentioned liquid 1,2-polybutadiene or liquid polyisobutylene can not only help the crosslinking agent, but also the role of a plasticizer, and can also make the rubber material have a higher hardness after vulcanization, which is suitable for high Where hardness is required. But they are all viscous liquid substances, which are not conducive to adding during processing, so their application is limited to a certain extent. In the prior art, a liquid auxiliary cross-linking agent can be pre-dispersed in a synthetic inorganic filler (such as calcium silicate) to form a polybutadiene powdery substance. It is very convenient to add during processing and has good properties with rubber compounds. Compatibility.

The unsaturated carboxylic acid metal salt includes at least one of zinc acrylate, zinc methacrylate, magnesium methacrylate, calcium methacrylate, and aluminum methacrylate. Ionic crosslinking can occur when unsaturated carboxylic acid metal salts such as zinc acrylate or zinc methacrylate are used as peroxide cross-linking agents, and the ionic bonds show good thermal aging stability and slip characteristics. The properties of oxide and sulfur vulcanization can give rubber a good tensile strength, tear strength and heat resistance. In addition, unsaturated carboxylic acid metal salts can also be used as a binder to improve the adhesion of rubber compounds to synthetic fibers, metals or other rubber compounds.

A further technical solution is that the plasticizer includes at least one of stearic acid, rosin oil, motor oil, naphthenic oil, paraffin oil, coumarone, RX-80, paraffin, liquid polyisobutylene, and dioctyl sebacate. One.

A further technical solution is that the metal oxide includes at least one of zinc oxide, magnesium oxide, and calcium oxide. Nano-zinc oxide, nano-magnesium oxide, or nano-calcium oxide having a particle size range of 10 to 100 nm is preferred, and a mixture of nano-zinc oxide and nano-magnesia is more preferred. The amount of nano-metal oxide added is preferably 5-20 parts by mass. The addition of metal oxides not only plays an activation role, but also nano-zinc oxide and nano-magnesium oxide can play the role of high temperature resistance, and can play a role of heat conduction for the vulcanization and application of thick products. In addition, the nano-scale oxide has a large specific surface area and a large activity, which is conducive to absorbing the acidic substances released during the aging of the rubber, and has obvious protective effects.

In a further technical solution, the surface modifier includes at least one of polyethylene glycol, diphenylsilicon glycol, triethanolamine, a silane coupling agent, and a titanate coupling agent. Wherein the molecular weight of polyethylene glycol is preferably 2000 or 3400 or 4000; the silane coupling agent may be selected from, for example, vinyltriethoxysilane (A-151), vinyltrimethoxysilane (A-171), vinyltrimethoxysilane (2-methoxyethoxy) silane (A-172), γ-glycidyl ether oxypropyltrimethoxysilane (A-187), γ-mercaptopropyltrimethoxysilane (A-189), Bis (γ-triethoxysilylpropyl) tetrasulfide (Si69), γ-aminopropyltriethoxysilane (KH-550), etc .; The titanate coupling agent may be selected from, for example, titanium dioleoyl titanium Ethylene acid, isopropyl triisostearate, isopropyl trioleate, and the like.

When silica is contained in the reinforcing filler, it is preferred to add a surface modifier to reduce its activity to reduce the effect on vulcanization, and to promote the combination of silica and macromolecules, improve the dispersion of the rubber, reduce The formation of a filler network further improves the vulcanization characteristics, comprehensive physical properties, dynamic properties, and processability of silica reinforced compounds. For compounds containing peroxide crosslinking agents, vinyl-containing silanes are preferred.

A further technical solution is that 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).

A further technical solution is that the vulcanization accelerator includes 2-thiol benzothiazole, dibenzothiazole disulfide (DM), tetramethylthiuram monosulfide, and tetramethylthiuram disulfide (TMTD). , Tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolyl sulfenamide (CZ), N, N-dicyclohexyl-2-benzothiazolyl sulfenamide, N-oxydiethyl At least one of a phenylene-2-benzothiazolyl sulfenamide, a bismaleimide, and an ethylenethiourea.

A further technical solution is that the compatibilizer can be selected from epoxidized natural rubber, functionally modified ethylene-propylene rubber, or branched polyethylene, and the functionally modified monomer used can be selected from maleic anhydride (MAH) , Methacrylic acid (MA), acrylic acid (AA), itaconic acid (IA), fumaric acid (FA), isocyanate, glycidyl methacrylate (GMA), methyl methacrylate (MMA), Fumar Dibutyl acid (DBF), β-hydroxyethyl methacrylate (HEMA), dibutyl maleate (DBM), diethyl maleate (DEM), halogen element (such as liquid chlorine, liquid bromine, etc. ), Halogen-containing compounds (such as N-bromosuccinimide, bromodimethylhydantoin, carbon adsorbing chlorine, carbon adsorbing bromine, etc.), sulfur-containing compounds (such as sulfur dioxide, sulfinyl chloride, etc.), vinyl Trimethoxysilane (VTMS), vinyltriethoxysilane (VTES), 3-methacryloxypropyltrimethoxysilane (VMMS), styrene (St), α-methylstyrene ( α-MSt), acrylonitrile (AN), and the like, or mixtures thereof, are used to improve the compatibility, blending, and co-vulcanizability between branched polyethylene (and ethylene-propylene rubber) and natural rubber. As the compatibilizer, trans polyoctene elastomer can also be used, which can make the glue used together to form a more uniform shape, thereby improving compatibility. The glass transition temperature of branched polyethylene and ethylene-propylene rubber with high ethylene content is relatively low, and grafting a certain amount of polar functional groups, such as styrene, α-methylstyrene, etc., is beneficial to increase their glass transition temperature. Therefore, when the rubber composition of the present invention is applied to a tire tread, it can contribute to improving the wet skid resistance of the composition.

In a further technical solution, the tackifier includes at least one of petroleum resin, terpene resin, rosin and derivatives, and coomarone resin.

In a further technical solution, the adhesive includes at least one of a resorcinol donor, a methylene donor, an organic cobalt salt, a maleic anhydride butadiene resin, and a liquid natural rubber.

The resorcinol donor may be selected from, for example, resorcinol (Binder R), Binder RS, Binder RS-11, Binder R-80, Binder RL, Binder PF , Adhesive PE, adhesive RK, adhesive RH, etc .; the methylene donor can be selected from, for example, hexamethylenetetramine (HMTA), adhesive H-80, adhesive A, adhesive RA, Adhesive AB-30, Adhesive Rq, Adhesive RC, Adhesive CS963, Adhesive CS964, etc .; the organic cobalt salt may be selected from, for example, cobalt naphthenate, cobalt neodecanoate, cobalt borate And cobalt stearate. A resorcinol donor, a methylene donor, and silica are used in combination to form a m-methylene-white system with excellent adhesive properties. The m-a-white system is used in combination with an organic cobalt salt, and the formed m-a-white-cobalt system can further improve the bonding effect and enhance the durability. By compounding the adhesive, the rubber material can be more suitable for the occasion where the adhesive performance is required such as the adhesive layer of the conveyor belt or the core rubber, the rubber layer in the hose, and the radial tire belt layer.

A further technical solution is that the aforementioned flame retardant includes aluminum hydroxide, magnesium hydroxide, zinc borate, antimony trioxide, zinc stearate, titanate, decabromodiphenyl ether, and a silane coupling agent modified At least one of hydroxide, red phosphorus, pentaerythritol, ammonium polyphosphate, and triethyl phosphate.

In a further technical solution, the foaming agent includes sodium bicarbonate, azobiscarboxamide (AC), dinitrosopentamethylenetetramine (H), diphenylsulfonyl hydrazide ether (OBSH), and benzenesulfonyl At least one of hydrazine (BSH), urea, and low-boiling-point hydrocarbon-containing microcapsule-type blowing agent. The above rubber composition containing a foaming agent is particularly suitable for producing lightweight and elastic sole materials.

A further technical solution is that, in 100 parts of the rubber matrix, 0 to 40 parts of styrene-butadiene rubber and 0 to 40 parts of polybutadiene rubber are further included. Styrene butadiene rubber can improve the stiffness of the rubber during processing, facilitate better molding and processing, and also improve the abrasion resistance and wet skid resistance of vulcanized rubber. The polybutadiene rubber is preferably a butyl rubber grade having a cis-structure content of not less than 90%, which can improve the cold resistance and abrasion resistance of the vulcanizate and reduce dynamic heat generation.

The rubber composition of the present invention is usually in a suitable mixing device (such as an internal mixer or an open mixer). First, all components except the crosslinking system components such as a cross-linking agent, a vulcanization accelerator, and an auxiliary cross-linking agent are mixed. It is kneaded, and the temperature of the kneading may be from room temperature or below to 150 ° C or higher. If the debinding temperature is higher than the activation temperature of the crosslinking agent, it needs to be cooled below the activation temperature after debinding. The cross-linking system is then blended into the blend by subsequent mixing.

Due to the uneven distribution of various fillers in the rubber phases of the combined rubber when the above-mentioned mixing method is used, it will lead to negative effects such as uneven vulcanization or stress concentration, resulting in a decline in the physical and mechanical properties of the combined rubber vulcanized rubber. One of the solutions is to add most of the filler to rubber with low unsaturation and low polarity to make a masterbatch, then add the combined rubber, and then add the remaining small part of the filler, and continue to press Traditional method of mixing; the second solution is to mix the two rubbers to be mixed together and then mix according to the proportion.

The invention provides a method for processing the above rubber composition, which adopts a masterbatch method for rubber mixing: let the proportion of branched polyethylene and ethylene-propylene rubber be a%, and the proportion of the remaining components including natural rubber be b %, Set branched polyethylene and ethylene-propylene rubber as the rubber matrix of the master batch (A), and set the remaining components in the rubber matrix including natural rubber as the rubber matrix of the master batch (B), It is characterized in that in the mixing stage of the master batch, the reinforcing filler is distributed to the master batch (A) at a ratio higher than a%, and the peroxide cross-linking agent is allocated to the compound at a ratio higher than a% Masterbatch (A).

A further technical solution is that the method for kneading the rubber composition includes the following steps:

Step 1: Plasticize the natural rubber on an open mill;

Step 2: Mixing in an internal mixer to obtain two types of masterbatch;

Step 3: The master batch (A) and the master batch (B) are mixed in a mixer in proportion to obtain the final compound (C). The final compound (C) is thinned on the open mixer and then lowered. Film, parked, waiting for further processing.

The present invention also provides a rubber support, and the rubber used comprises the above rubber composition.

A further technical solution is that in order to reduce the effects of creep and stress relaxation on the performance of the above rubber bearings, the amount of plasticizer in the rubber composition is preferably 0-15 parts, and more preferably liquid polyisobutylene, liquid ethylene-propylene rubber, etc. Low molecular weight polymer plasticizer.

The rubber bearing may be a bridge plate rubber bearing, a basin rubber bearing, or a vibration-isolating rubber bearing.

The rubber bearing produced by using the rubber composition provided by the present invention can not only have excellent elasticity, fatigue resistance and physical and mechanical properties of natural rubber, but also have ozone resistance and weathering resistance of ethylene-propylene rubber or branched polyethylene. Because the branched polyethylene has a high molecular weight and a narrow molecular weight distribution (about 2), after the introduction of the branched polyethylene, the vulcanizate can obtain good physical and mechanical properties and resistance to compression and permanent deformation.

The present invention provides a tire comprising at least one of a rubber compound for a sidewall and a tread thereof including the above rubber composition.

Ethylene-propylene rubber is not suitable for tire tread alone because of its poor wet skid resistance, low mechanical strength, and poor adhesion. In the prior art, ethylene-propylene rubber is often added to the tread or sidewall rubber to improve its weather resistance and ozone aging resistance. By introducing branched polyethylene to replace part or all of ethylene-propylene rubber, it is possible to improve the tire tread or While improving the weather resistance, ozone aging resistance and high temperature resistance of the sidewall, the overall physical and mechanical properties are improved. Further use of styrene-butadiene rubber in the tread rubber can improve the wet skid resistance and abrasion resistance of the tread rubber, and further use of butyl rubber in the tread rubber can improve the wear resistance of the tread rubber and reduce dynamic heat generation . The addition of butadiene rubber to the sidewall rubber can reduce the dynamic heat generation of the sidewall, improve its resistance to flexion, and extend its service life. A further technical solution is that in order to improve the wet skid resistance of the rubber composition by increasing the overall glass transition temperature, the ethylene-propylene rubber used in the present invention is preferably a ethylene-propylene rubber with a high propylene content, and specifically, a propylene content of 60 is preferred. % To 95% of ethylene-propylene rubber, the Tg is generally not lower than -40 ° C, preferably the Tg is not lower than -30 ° C.

A further technical solution is that the tire is a power tire.

A further technical solution is that the tire is a radial tire or a bias tire.

A further technical solution is to use the rubber composition provided by the present invention on the sidewall and tread of the tire at the same time to improve co-vulcanization and adhesion between the two, thereby improving the overall quality of the tire.

A further technical solution is that at least one of a tire rubber, a belt layer, and a carcass ply in the radial tire comprises the rubber composition described above. By using the above-mentioned rubber composition, the co-vulcanizability of the entire tire and the adhesion between various parts can be improved.

The invention provides a conveyor belt, which includes a working surface covering rubber and a non-working surface covering rubber. A tensile layer is provided between the working surface covering rubber and the non-working surface covering rubber. The working surface covering rubber and the non-working surface covering rubber are provided. The rubber used in at least one layer of the gum comprises the rubber composition described above.

The present invention provides a canvas core conveyor belt. The rubber used in the adhesive layer includes the rubber composition.

The rubber composition for the adhesive layer may use a certain amount of low molecular weight polymer plasticizer liquid polyisobutylene, liquid polybutadiene, or liquid ethylene-propylene rubber to reduce the viscosity of the branched polyethylene and / or ethylene-propylene rubber. Improve its self-adhesion, and improve the blending and dispersing effect with natural rubber.

A further technical solution is that the rubber composition used in at least one of the working surface covering rubber and the non-working surface covering rubber of the canvas core conveyor belt contains 5 to 100 parts by weight of branched polyethylene per 100 parts by weight of the rubber matrix. The canvas used is any of cotton canvas, vinylon canvas, nylon canvas, polyester canvas, straight-weft polyester-nylon canvas, and aramid canvas.

The invention provides a rope core conveyor belt. The rubber used for the adhesive core rubber of the rope core conveyor belt comprises the rubber composition described above.

A further technical solution is that the rubber composition used in at least one of the working surface covering rubber and the non-working surface covering rubber of the core conveyor belt contains 5 to 100 parts by weight of branched polyethylene per 100 parts by weight of the rubber matrix. The rope core is a steel wire rope core or a polymer rope core, and the polymer rope core used is preferably a high-strength rope core such as an aramid rope core or an ultra-high molecular weight polyethylene fiber core.

The adhesive rubber used for the canvas core conveyor belt or the rubber composition used for the adhesive core rubber used for the rope core conveyor belt may further include 2 to 5 parts of short fibers for improving the modulus and improving the overall modulus distribution of the conveyor belt. The staple fiber is preferably a product having a pretreated surface and a good blending property with non-polar rubber.

The invention provides a conveyor belt having a buffer rubber between a covering rubber and an adhesive rubber, and the rubber used for the buffer rubber comprises the rubber composition described above. A further technical solution is that the rubber composition used in at least one layer of the working surface covering rubber and the non-working surface covering rubber comprises 5 to 100 parts by weight of branched polyethylene per 100 parts by weight of the rubber matrix.

The invention provides a rubber tube, which includes an inner rubber layer, a reinforcing layer, and an outer rubber layer. The rubber used in at least one of the inner rubber layer and the outer rubber layer includes the rubber composition described above.

The invention provides a rubber tube, which comprises an inner rubber layer, a first reinforcement layer, a middle rubber layer, a second reinforcement layer and an outer rubber layer from the inside to the outside, wherein the middle rubber layer of the rubber tube comprises the rubber composition described above. In a further technical solution, the rubber composition used in at least one of the outer rubber layer and the inner rubber layer comprises 5 to 100 parts by weight of branched polyethylene per 100 parts by weight of the rubber matrix.

The use of styrene-butadiene rubber in the inner or outer rubber layer of the hose can mention the stiffness of the rubber, which is especially suitable for the inner rubber layer of the hose formed by the coreless method to improve the setting.

The use of butadiene rubber in the inner or outer rubber layer of the hose can improve the corrosion resistance and elasticity of the vulcanized rubber, and is particularly suitable for the working layer of abrasion-resistant rubber hoses, such as the inner rubber layer of sandblasted hoses.

The present invention provides a power transmission belt having a main body of a certain length including a buffer rubber layer and a compression rubber layer, and the rubber used in at least one of the buffer rubber layer and the compression rubber layer includes the above rubber composition. The compression rubber layer includes short fibers, and the buffer rubber layer does not include short fibers.

The present invention provides a rubber roller comprising a rubber composition as described above.

The present invention provides a shoe sole using a rubber comprising the rubber composition described above.

A further technical solution is that a foaming agent is contained in the rubber composition for a shoe sole.

A further technical solution is that the reinforcing filler in the rubber composition for a sole described above includes silica having a particle size of not more than 50 nm, preferably a particle size of 15 to 20 nm, which has transparency and reinforcement.

The present invention provides a rubber shoe having a midsole, and the rubber used in the midsole comprises the rubber composition described above.

The beneficial effects of the present invention are:

First, the molecular structure of the branched polyethylene is completely saturated, and the heat-resistant aging performance is similar to that of the ethylene-propylene rubber, which is better than the ethylene-propylene rubber, and because the branched polyethylene has a relatively high molecular weight and unique branched chain The structure can have better mechanical strength after cross-linking, so it can improve the overall aging resistance and physical and mechanical properties.

Second, at the same molecular weight and amount, branched polyethylene can form a continuous phase more easily than ethylene-propylene rubber, so that it can obtain better aging resistance and physical and mechanical properties as a whole.

Third, because branched polyethylene can obtain better mechanical strength after cross-linking, it can reduce the effect on the physical and mechanical properties of natural rubber when the combined ratio of branched polyethylene is increased, so that the vulcanizate At the same time, it has good aging resistance and physical and mechanical properties.

Fourth, combined with natural rubber, it can improve the adhesion properties of ethylene-propylene rubber and / or branched polyethylene, and can be better used in places where aging resistance and adhesion are required.

Fifth, the molecular weight distribution of branched polyethylene is narrower than that of ethylene-propylene rubber and natural rubber, so it can give the rubber good resistance to compression and permanent deformation.

The above beneficial effects can make the rubber composition more suitable for applications such as tires, hoses, conveyor belts, transmission belts, and rubber bearings that require aging resistance, physical and mechanical properties, bonding properties, and fatigue resistance.

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. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still belong to the protection scope of the present invention. .

Specific embodiments of the rubber composition provided by the present invention are:

Provided is a rubber composition comprising a rubber matrix, a reinforcing filler and a cross-linking agent, characterized in that the 100 parts by weight of the rubber matrix contains more than 0 parts and not more than 99 parts of branched polymer. Ethylene, 0 to 90 parts of ethylene-propylene rubber and 1 to 95 parts of isoprene-based elastomer. Based on 100 parts by weight of the rubber matrix, the rubber composition contains 10 to 200 parts of a reinforcing filler, and 0.1 to 10 parts of a crosslinking agent. .

A preferred embodiment is that by weight parts, each 100 parts of the rubber matrix contains 10 to 95 parts of branched polyethylene, 0 to 60 parts of ethylene-propylene rubber and 5 to 90 parts of natural rubber; 100 parts by weight of rubber Based on the matrix, the rubber composition contains 15 to 150 parts of a reinforcing filler and 1 to 8 parts of a crosslinking agent.

The branched polyethylene used is a type of ethylene homopolymer with a degree of branching of not less than 50 branches / 1000 carbons. At present, its synthesis method mainly uses (α-diimide) nickel / palladium catalyst to prepare In situ polymerization catalyzes homopolymerization of ethylene. Branched polyethylene having a degree of branching of 50 to 150 branches / 1000 carbons is preferred, branched polyethylene having a degree of branching of 60 to 130 branches / 1000 carbons is more preferred, and weight of the branched polyethylene is preferred. The average molecular weight is 66,000 to 518,000, and Mooney viscosity ML (1 + 4) is 6 to 102 at 125 ° C.

The ethylene-propylene rubber used is preferably a tertiary or quaternary ethylene-propylene rubber having a Mooney viscosity ML (1 + 4) of 15 to 100 at 125 ° C and a weight ratio of diene monomers of 4% to 10%. Diene monomers are preferred. As the ENB, the diene monomer is more preferably an ethylene-propylene rubber having both ENB and VNB, or an ethylene-propylene rubber having ENB and VNB as the third monomer may be used in combination.

A preferred embodiment is that auxiliary ingredients can be added to the rubber composition to improve the performance of rubber compounds and products for various specific applications.

Auxiliary components such as cross-linking aids, plasticizers, metal oxides, stearic acid, surface modifiers, stabilizers, vulcanization accelerators, compatibilizers, tackifiers, adhesives, flame retardants, hair Foam and so on. Auxiliary ingredients are used in conventional amounts, depending on the application.

In a preferred embodiment, the auxiliary component further comprises 0 to 15 parts of a compatibilizer based on 100 parts by weight of the rubber matrix to improve co-vulcanization and physical compatibility between the combined rubbers.

In a preferred embodiment, the rubber base further comprises 0 to 40 parts of styrene-butadiene rubber and 0 to 40 parts of butadiene rubber. Styrene butadiene rubber can improve the stiffness of the rubber during processing, facilitate better molding and processing, and also improve the abrasion resistance and wet skid resistance of vulcanized rubber. Butadiene rubber can improve the cold resistance and abrasion resistance of vulcanizates, making the rubber composition more suitable for specific applications.

For the processing method of the rubber composition provided by the present invention, a masterbatch mixing process is mainly used. Specifically, the proportion of branched polyethylene and ethylene-propylene rubber is set to a%, and the proportion of the remaining components including natural rubber is b%, the branched polyethylene and ethylene-propylene rubber are set as the rubber matrix of the master batch (A), and the remaining components including the natural rubber in the rubber matrix are set as the rubber matrix of the master batch (B) , Which is characterized in that in the mixing stage of the master batch, the reinforcing filler is distributed to the master batch (A) at a ratio higher than a%, and the peroxide cross-linking agent is distributed at a ratio higher than a% Mix the masterbatch (A).

A further embodiment is the method for processing the above rubber composition, comprising the following steps:

Step 1: Plasticize the natural rubber on an open mill;

Step 2: Mixing in an internal mixer to obtain two types of masterbatch;

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

The Mooney viscosity ML (1 + 4) of the selected ethylene-propylene rubber and ethylene-propylene rubber is preferably 20 to 80 at 125 ° C, the ethylene content is preferably 45% to 70%, and the third monomer content is preferably 4% to 12 %.

Specifically, the ethylene-propylene rubber used in the embodiments of the present invention is selected from the following table:

乙丙橡胶编号Ethylene-propylene rubber number	乙烯含量/％Ethylene content /%	门尼粘度Mooney viscosity	第三单体含量/％Third monomer content /%
EPDM-1EPDM-1	7070	ML(1+4)125℃：55ML (1 + 4) 125 ℃ ： 55	4.54.5
EPDM-2EPDM-2	5050	ML(1+4)125℃：30ML (1 + 4) 125 ℃ ： 30	88
EPDM-3EPDM-3	5050	ML(1+4)125℃：65ML (1 + 4) 125 ℃ ： 65	99
EPDM-4EPDM-4	5555	ML(1+8)100℃：55ML (1 + 8) 100 ℃ ： 55	11.511.5

The selected branched polyethylene is characterized by a degree of branching 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 to 6 to 102. . Among them, the degree of branching was measured by nuclear magnetic hydrogen spectroscopy, and the mole percent content of various branch chains was measured by nuclear magnetic carbon spectroscopy.

The details are as follows:

Rubber performance test method:

1. Hardness test: According to the national standard GB / T 531.1-2008, use a hardness tester to test, the test temperature is room temperature;

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

3. Mooney viscosity test: According to GB / T1232.1-2000, test with Mooney viscosity meter;

4. Hot air accelerated aging test: According to the national standard GB / T3512-2001, conducted in a thermal aging test box;

5. Adhesive strength test: According to the national standard GB6759-86, the adhesive strength of rubber and canvas layers is tested. At a speed of 100 mm / min on a tensile machine, a certain length of peeling was caused between the adhesive layers of the sample according to the "one layer at a time" method (A method), and the adhesive strength was calculated using the automatically recorded peel force curve. The adhesive strength at a high temperature was measured on the high-temperature tensile tester by the above-mentioned A method.

6. Compression permanent deformation test: According to the national standard GB / T7759-1996, use the compression permanent deformation device for testing. Type B, the compression amount is 25%, and the test temperature is 70 ° C;

7. Ozone resistance aging test: According to the national standard GB / T7762-2003, in an ozone aging phase box, under a certain static tensile strain condition, exposed to a certain ozone concentration in the air, at a specified temperature (40 ° C) without Resistance to ozone cracking in environments directly affected by light;

8. Tc90 test of positive vulcanization time: conducted in a rotorless vulcanizer in accordance with national standard GB / T16584-1996.

Unless otherwise specified, the vulcanization conditions of the following Examples 1-28 and Comparative Examples 1-6 are unified as: temperature: 160 ° C; pressure: 16MPa; vulcanization time for samples less than 6mm is Tc90 + 2min; thickness is not low The vulcanization time of the sample at 6mm is Tc90 + 8min.

The basic formulations of Examples 1 to 6 and Comparative Examples 1 and 2 are shown in Table 1: (which lists the weight parts of each component used per 100 weight parts of the rubber matrix)

Table 1

The formulations of Examples 1 and 2 and Comparative Example 1 were processed according to the following method: 50% (mass fraction) of carbon black (based on the amount of carbon black in the basic formula, the same applies below), 50% DCP, and ethylene-propylene rubber Mix with branched polyethylene to obtain a masterbatch, and then mix the natural rubber after mixing with the aforementioned masterbatch for 1 minute, then add the remaining carbon black and cross-linking agent in sequence, and then mix two two-part rubbers. . The mixed rubber was thinned on an open mill with a roller temperature of 60 ° C., and the roll distance was enlarged to 2 mm, and the film was left for 20 hours. After being cured for 16 hours, various tests were performed.

The formulations of Examples 3 to 6 and Comparative Example 2 were processed according to the following method: 50% of zinc oxide, stearic acid and antioxidant, 70% of coumarone resin and carbon black, 70% of DCP and sulfur and ethyl Acrylic rubber and branched polyethylene are mixed to obtain a masterbatch (A). The plasticized natural rubber is then mixed with 50% zinc oxide, stearic acid and antioxidants, 30% coumarone resin and carbon black, 30% DCP and sulfur are mixed to obtain a masterbatch (B), and the masterbatch (A) and (B) are mixed in proportion to form a final rubber. After the final rubber mill was thinned on an open mill with a roller temperature of 60 ° C., the roll distance was enlarged to 2 mm, and the sheet was left for 20 hours. After being cured for 16 hours, various tests were performed.

The test results of Examples 1 to 6 and Comparative Examples 1 and 2 are shown in Table 2:

Table 2

Analysis of test results: Through comparison of Examples 1, 2 and Comparative Example 1, it can be found that partially or totally replacing ethylene-propylene rubber with branched polyethylene of the same Mooney viscosity can significantly improve the overall physical and mechanical properties, and can have more Low compression permanent deformation, aging resistance is improved but not significant, mainly because the amount of ethylene-propylene rubber and branched polyethylene is 80 parts, the system itself has excellent aging resistance. Through comparison of Examples 3 to 6 and Comparative Example 2, it can be found that replacing some or all of ethylene-propylene rubber with a branched polyethylene having a lower Mooney viscosity can improve the overall aging resistance and physical and mechanical properties at the same time. This is mainly Because, compared with ethylene-propylene rubber, partially branched polyethylene can have lower Mooney viscosity and higher molecular weight at the same time, low Mooney viscosity can make ethylene-propylene rubber and branched polyethylene more easily form a continuous phase, thus Give the system better aging resistance, and the use of branched polyethylene can also improve physical and mechanical properties. It will not make ethylene-propylene rubber more easily form a continuous phase like traditional oil softeners, but it will lead to the overall The degradation of physical and mechanical properties is one of the main beneficial effects of the present invention.

The formulations described in Examples 1 to 6 can be better applied to rubber bearing applications due to their better aging resistance, physical and mechanical properties, and compression set resistance.

The basic formulations of Examples 7 to 11 and Comparative Example 3 are shown in Table 3: (which lists the weight parts of each component used per 100 weight parts of the rubber matrix)

table 3

The formulations of Examples 7 to 11 and Comparative Example 3 were processed according to the following method: 50% of carbon black, calcium carbonate and calcined clay, 50% of zinc oxide and stearic acid, all DCP and TAIC, 50% of sulfur and The accelerator is first mixed with ethylene-propylene rubber and branched polyethylene to obtain a masterbatch, and then the remaining rubber matrix components (natural rubber is first plasticized) are mixed with the aforementioned masterbatch for 1 minute, and then the remaining The components are mixed for 2 minutes and then discharged. The mixed rubber was thinned on an open mill with a roller temperature of 60 ° C., and the roll distance was enlarged to 2 mm, and the film was left for 20 hours. After being cured for 16 hours, various tests were performed.

The test results of Examples 7 to 11 and Comparative Example 3 are shown in Table 4:

Table 4

Analysis of test results: Through comparison between Example 7 and Comparative Example 3, it can be found that by replacing a part of ethylene-propylene rubber with a small amount of high molecular weight branched polyethylene, the overall physical and mechanical properties can be improved without affecting the original improvement of aging resistance. By comparing Example 8 and Comparative Example 3, it can be found that when the amount of branched polyethylene is high, the tear strength can be significantly improved, and it can also be understood as reducing the original tear of natural rubber by adding ethylene-propylene rubber. The effect of cracking strength means that the compound can be used with more branched polyethylene to improve the aging resistance of the compound without significantly affecting the physical and mechanical properties of the compound. The performance of 9 and 10 is confirmed. According to the experience of the prior art, where there is a further requirement for wet skid resistance or abrasion resistance, a certain amount of styrene-butadiene rubber can also be used to improve it.

The formulas of Examples 7 to 11 are mainly applicable to the places with high requirements on aging resistance and physical and mechanical properties, especially the places with high requirements on tearing properties, such as the outer tread rubber of power tires. If it is desired to further improve the moisture resistance Sliding and abrasion resistance, you can use an appropriate amount of styrene-butadiene rubber.

The basic formulations of Examples 12 and 13 and Comparative Example 4 are shown in Table 5: (which lists the weight parts of each component used per 100 weight parts of the rubber matrix)

table 5

The formulations of Examples 12 and 13 and Comparative Example 4 were processed according to the following method: 50% of carbon black, 50% of zinc oxide and stearic acid, all DCP and TAIC, 50% of sulfur and accelerator were first mixed with ethylene propylene The rubber and the branched polyethylene are mixed to obtain a masterbatch, and the remaining rubber matrix components (natural rubber is first plasticized) are mixed with the aforementioned masterbatch for 1 minute, and then the remaining components are added in the usual order and mixed. 2 Discharge in minutes. The mixed rubber was thinned on an open mill with a roller temperature of 60 ° C., and the roll distance was enlarged to 2 mm, and the film was left for 20 hours. After being cured for 16 hours, various tests were performed.

The test results of Examples 12 and 13 and Comparative Example 4 are shown in Table 6:

Table 6

Analysis of test data: Through comparison of Examples 12 and 13, and Comparative Example 4, it can be found that the technical solution of replacing part or all of ethylene-propylene rubber with branched polyethylene is applicable to sidewall rubber, compared with the existing combination of ethylene-propylene rubber In a technical solution, the sidewall rubber formula provided by the present invention can impart better aging resistance, physical and mechanical properties, and compression resistance to permanent deformation to the sidewall rubber by introducing a branched polyethylene having a narrow molecular weight distribution and a high molecular weight. The sidewall may be a sidewall of a power tire or a sidewall of an automobile tire.

The invention provides a rubber composition for bonding, which can be used for bonding non-polar rubbers such as branched polyethylene, ethylene-propylene rubber, and the like, and reinforcing materials such as fibers, canvas, and steel wire rope cores. The final product may be a hose, a conveyor belt, or other rubber products containing a reinforcing layer.

Examples of the rubber composition for bonding are Examples 14 to 20 and Comparative Example 5.

The basic formulations of Examples 14 to 20 and Comparative Example 5 are shown in Table 7: (which lists the weight parts of each component used per 100 weight parts of the rubber matrix)

Table 7

The formulations of Examples 14 to 20 and Comparative Example 5 were processed according to the following method: zinc oxide, stearic acid, binder RS, tackifier, carbon black, white carbon, 50% of softener, all DCP and TAIC, 50% sulfur and accelerator are firstly mixed with ethylene-propylene rubber and branched polyethylene to obtain a masterbatch, and then the remaining rubber matrix components (natural rubber is first plasticized, and the Mooney viscosity ML (1+ 4) 100 ° C is about 40) and mix with the aforementioned masterbatch for 2 minutes, and then add the remaining components in the usual order, control the mixing temperature to 60 ° C to 80 ° C, and discharge the mixture after 5 minutes of mixing. The compounded rubber is thinned on an open mill with a roller temperature of 60 ° C., and the roll distance is enlarged to 2 mm, and the film is left for 20 hours. Then, it is laminated with polyester canvas or aramid canvas impregnated at room temperature and vulcanized at 180 ° C. Adhesive samples were obtained and tested after 16 hours of standing.

The performance test results of Examples 14 to 20 and Comparative Example 5 are shown in Table 8:

Table 8

Analysis of test data: Through comparison of Examples 14 to 17 and Comparative Example 5, it can be found that: using a branched polyethylene with a low Mooney viscosity instead of part of ethylene-propylene rubber in combination with natural rubber, while reducing the amount of softener, can effectively improve The adhesive strength of the adhesive layer with polyester canvas before and after aging and at high temperature is mainly because the branched polyethylene with low Mooney viscosity can give the adhesive layer better fluidity, and improve the adhesion of the rubber and polymer of the adhesive layer. The permeability between the ester canvas and the cross-linking effect inside the rubber compound of the embodiment of the present invention is better than that of a rubber compound containing a large amount of a common low molecular weight softener. However, in Comparative Examples 15 to 17, it can also be found that with the decrease in the amount of ethylene-propylene rubber, the adhesive strength before aging gradually decreases, which indicates that ethylene-propylene rubber with a high third monomer content can increase the polarity of the branched polyethylene phase. It can effectively promote co-vulcanization between branched polyethylene and natural rubber, and can also promote co-vulcanization with the polyester canvas dipping interface, so the use of some ethylene-propylene rubber with a high third monomer content can be used as a preference. In addition, it can be seen from Example 18 that without the use of ethylene-propylene rubber, adding an adhesive such as maleic anhydride butadiene resin can significantly improve the adhesion of the adhesive layer to the polyester canvas before and after aging and at high temperatures. The adhesion strength. Example 19 shows that by increasing the combined ratio of natural rubber, the absolute value of the adhesive strength before and after aging can be increased, but the retention rate is reduced, and the adhesive strength at 150 ° C is also low, which shows that this formula is more suitable for resistance to High temperature resistant conveyor belts with a thermal rating of T1 or T2. Example 20 shows very high pre-aging adhesive strength, the main reason is that styrene-butadiene rubber can be better co-vulcanized with the butylpyridine latex used for canvas dipping, and the interface compatibility is better, and the aramid is more polar High, can also promote self-adhesion with adhesive layer rubber.

The rubber compositions for bonding described in Examples 14 to 20 and Comparative Example 5 can be used as the adhesive layer of a high-temperature resistant conveyor belt or the middle rubber layer of a hose.

When the above rubber composition for adhesion is used as the adhesive layer, if the covering rubber of the conveyor belt uses branched polyethylene as the main rubber matrix, the entire conveyor belt can have better co-vulcanization, processing performance and product use. Better performance. If the heat resistance level of the conveyor belt is not high, or there are high requirements for mechanical strength, wear resistance or cold resistance, you can consider branched polyethylene or ethylene-propylene rubber and diene rubber such as natural rubber, styrene butadiene Use rubber or butyl rubber together, each with its own strengths and complementary advantages.

Examples of the rubber compositions used in combination include Examples 21 to 26 and Comparative Examples 6 and 7.

The basic formulations of Examples 21 to 26 and Comparative Examples 6 and 7 are shown in Table 9: (which lists the weight parts of each component used per 100 weight parts of the rubber matrix)

Table 9

The formulations of Examples 21, 22, 26 and Comparative Example 7 were mixed according to a traditional mixing process: after natural rubber was plasticized, it was put into an internal mixer with ethylene-propylene rubber and branched polyethylene for 2 minutes; then Add zinc oxide, stearic acid and antioxidant, and mix for 1 minute; then add calcium carbonate and carbon black and mix for 30 seconds; then add softener and mix for 2 minutes; then add the remaining components and mix for 2 minutes. After mixing the compounded rubber on an open mill with a roller temperature of 60 ° C., enlarge the roll distance to 2 mm, and leave it for 20 hours. After curing, leave it for 16 hours for testing.

Examples 23, 24, 25 and Comparative Example 6 were processed according to the following method: 50% of carbon black, 50% of zinc oxide, stearic acid, antioxidants and coumarone resins, all DCP and TAIC, 50% Sulfur and accelerator are first mixed with ethylene-propylene rubber and branched polyethylene to obtain a masterbatch. Then the remaining rubber matrix components (natural rubber is first plasticized) are mixed with the aforementioned masterbatch for 1 minute, and then added in the usual order. The remaining components are mixed for 2 minutes and then discharged. The mixed rubber was thinned on an open mill with a roller temperature of 60 ° C., and the roll distance was enlarged to 2 mm, and the film was left for 20 hours. After being cured for 16 hours, various tests were performed.

The test results of Examples 21 to 26 and Comparative Examples 6 and 7 are shown in Table 10:

Table 10

Analysis of test data: Through comparison between Example 21 and Comparative Example 7, it can be found that branched polyethylene and a small amount of natural rubber can slightly improve the physical and mechanical properties of the rubber without affecting the aging resistance of the rubber. The reason may be that natural rubber is distributed in branched polyethylene with a very small particle size. When the branched polyethylene is subjected to destructive stress, the excellent self-reinforcing effect of natural rubber can be used to suppress cracks to a certain extent. Fast growth, thereby improving the physical and mechanical properties of the compound.

Claims

A rubber composition comprising a rubber matrix, a reinforcing filler and a cross-linking agent, characterized in that the 100 parts of the rubber matrix comprises more than 0 parts and not more than 99 parts of branched polyethylene per 100 parts of the rubber matrix, 0 to 90 parts of ethylene-propylene rubber and 1 to 95 parts of isoprene-based elastomer, wherein the branched polyethylene is an ethylene homopolymer having a branched structure.
The rubber composition according to claim 1, wherein the degree of branching of the branched polyethylene is 50 to 150 branches / 1000 carbons.
The rubber composition according to claim 2, wherein the degree of branching of the branched polyethylene is 60 to 130 branches / 1000 carbons.
The rubber composition according to claim 3, wherein the weight average molecular weight of the branched polyethylene is 66,000 to 518,000, and the Mooney viscosity ML (1 + 4) is 6 to 102 at 125 ° C.
The rubber composition according to claim 1, wherein the ethylene-propylene rubber comprises at least one of ethylene-propylene rubber, ethylene-propylene rubber, and ethylene-propylene rubber.
The rubber composition according to claim 5, wherein the comonomers of the ethylene-propylene diene rubber and ethylene-propylene diene rubber include diene monomers, and the diene monomers contain 5- At least one of ethyl-2-norbornene, 5-vinyl-2-norbornene, dicyclopentadiene, and 1,4-hexadiene.
The rubber composition according to claim 6, wherein the weight ratio of the diene monomer to the ethylene-propylene rubber is 1% to 14%.
The rubber composition according to claim 1, wherein the isoprene-based elastomer comprises at least one of natural rubber, synthetic polyisoprene, and an isoprene copolymer.
The rubber composition according to claim 8, wherein the isoprene copolymer comprises a butadiene-isoprene copolymer, an isoprene-styrene copolymer, and a butadiene-isoprene At least one of pentadiene-styrene copolymers.
The rubber composition according to claim 1, wherein the isoprene-based elastomer is a natural rubber.
The rubber composition according to claim 1, wherein the rubber composition comprises 10 to 200 parts of a reinforcing filler based on 100 parts by weight of a rubber matrix.
The rubber composition according to claim 1, wherein the reinforcing filler comprises carbon black, white carbon black, calcium carbonate, calcined clay, talc, magnesium silicate, aluminum silicate, magnesium carbonate, titanium At least one of white powder, montmorillonite, and short fibers.
The rubber composition according to claim 1, wherein the rubber composition comprises 0.1 to 10 parts of a crosslinking agent based on 100 parts by weight of a rubber matrix.
The rubber composition according to claim 1, wherein the crosslinking agent comprises at least one of a peroxide crosslinking agent and sulfur, and the peroxide crosslinking agent is di-t-butyl peroxide Compounds, dicumyl peroxide, t-butylcumyl 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-3-hexyne, bis (tert-butylperoxyisopropyl) Propyl) benzene, 2,5-dimethyl-2,5-di (benzoic acid peroxide) hexane, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexyl carbonate At least one.
The rubber composition according to claim 1, characterized in that, based on parts by weight, the rubber base comprises 10 to 95 parts of branched polyethylene, 0 to 60 parts of ethylene-propylene rubber and 5 to 90 parts per 100 parts of the rubber matrix. Natural rubber; based on 100 parts by weight of the rubber matrix, the rubber composition further comprises 15 to 150 parts of a reinforcing filler and 1 to 8 parts of a crosslinking agent.
The rubber composition according to any one of claims 1 to 15, wherein the rubber composition further comprises an auxiliary component.
The rubber composition according to claim 16, wherein the auxiliary component comprises a cross-linking aid, a plasticizer, a metal oxide, stearic acid, a surface modifier, a stabilizer, a vulcanization accelerator, and a plasticizer. At least one of a compatibilizer, a tackifier, an adhesive, a flame retardant, and a foaming agent.
The rubber composition according to claim 17, characterized in that, based on 100 parts by weight of the rubber matrix, the amount of the auxiliary component used ranges from 0.2 to 10 parts of a cross-linking aid, 0 to 80 parts of a plasticizer, and metal oxidation 3 to 30 parts, 0 to 3 parts of stearic acid, 0 to 15 parts of surface modifier, 1 to 6 parts of stabilizer, 0 to 5 parts of vulcanization accelerator, 0 to 15 parts of compatibilizer, and 0 of thickener ～ 5 parts, adhesives 0-20 parts, flame retardants 0-150 parts, foaming agents 0-20 parts.
The rubber composition according to claim 17, wherein the cross-linking aid comprises triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, Triethylene glycol dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, N, N'-m-phenylene bismaleimide, N, N'-bis At least one of furfurylacetone, 1,2-polybutadiene, an unsaturated carboxylic acid metal salt, and sulfur.
The rubber composition according to claim 17, wherein the plasticizer comprises stearic acid, rosin oil, motor oil, naphthenic oil, paraffin oil, gumalon, RX-80, paraffin, liquid polyisobutylene And at least one of dioctyl sebacate.
The rubber composition according to claim 17, wherein the surface modifier comprises one of polyethylene glycol, diphenylsilicondiol, triethanolamine, a silane coupling agent, and a titanate coupling agent. At least one.
The rubber composition according to claim 17, wherein the stabilizer comprises 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6-ethoxy- At least one of 2,2,4-trimethyl-1,2-dihydroquinoline (AW) and 2-mercaptobenzimidazole (MB).
The rubber composition according to claim 17, wherein the vulcanization accelerator comprises 2-thiol benzothiazole, dibenzothiazole disulfide, tetramethylthiuram monosulfide, and tetramethyl disulfide Kithiuram, tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolyl sulfenamide, N, N-dicyclohexyl-2-benzothiazolyl sulfenamide, N-oxydi At least one of ethylene-2-benzothiazolylsulfenamide, bismaleimide, and ethylenethiourea.
The rubber composition according to claim 17, wherein the tackifier comprises at least one of a petroleum resin, a terpene resin, a rosin and a derivative thereof, and a coumarone resin.
The rubber composition according to claim 17, wherein the adhesive comprises a resorcinol donor, a methylene donor, an organic cobalt salt, a maleic anhydride butadiene resin, and a liquid natural rubber. At least one.
The rubber composition according to claim 1 to 15, characterized in that the 100 parts of the rubber matrix further comprises 0 to 40 parts of styrene-butadiene rubber and 0 to 40 parts of polybutadiene rubber per 100 parts of the rubber matrix.
A method for processing a rubber composition according to any one of claims 1 to 26, wherein the mixing process adopts a masterbatch method. Assuming that the proportion of branched polyethylene and ethylene-propylene rubber in the rubber matrix is a%, the branching will be branched. Polyethylene and ethylene-propylene rubber are set as the rubber base of the masterbatch (A), and the remaining components in the rubber base are set as the rubber base of the masterbatch (B), which is characterized in that the reinforcing filler is higher than The proportion of a% is assigned to the masterbatch (A), and the peroxide crosslinking agent is assigned to the masterbatch (A) at a proportion higher than a%.
A rubber support, characterized in that the rubber composition used comprises the rubber composition according to any one of claims 1 to 26.
The rubber bearing according to claim 28, wherein the rubber bearing is one of a bridge plate rubber bearing, a basin rubber bearing, or a vibration-isolating rubber bearing.
A tire characterized in that at least one of the rubber used for the sidewall and the tread of the tire comprises the rubber composition according to any one of claims 1 to 26.
The tire according to claim 30, wherein the tire is a power tire
The tire according to claim 30, wherein the tire is a radial tire or a bias tire.
The radial tire according to claim 32, comprising a shoulder rubber, a belt layer, and a carcass ply, wherein the rubber used in at least one of the shoulder rubber, the belt layer, and the carcass ply comprises The rubber composition according to claims 1 to 26.
A conveyor belt includes a working surface covering rubber and a non-working surface covering rubber, and a tensile layer is provided between the working surface covering rubber and a non-working surface covering rubber. The rubber used in at least one of the surface covering rubbers comprises the rubber composition according to any one of claims 1 to 26.
A canvas core conveyor belt, characterized in that there is an adhesive layer between the cover rubber and the dipped canvas of the canvas core conveyor belt, wherein the rubber used for the adhesive layer comprises the rubber composition according to any one of claims 1 to 26 .
The canvas core conveyor belt according to claim 35, wherein the rubber used in at least one of the working surface covering rubber and the non-working surface covering rubber comprises a rubber composition, and each 100 parts by weight of the rubber composition of the rubber composition Containing 5 to 100 parts by weight of branched polyethylene, the canvas used for the canvas core conveyor belt is any one of cotton canvas, vinylon canvas, nylon canvas, polyester canvas, straight-weft polyester-nylon canvas, and aramid canvas Species.
A cord conveyor belt, characterized in that the rubber used for bonding the core rubber of the cord conveyor belt comprises the rubber composition according to any one of claims 1 to 26.
The rope core conveyor belt according to claim 37, wherein at least one layer of the working surface covering rubber and the non-working surface covering rubber of the rope core conveyor belt comprises a rubber composition, and each of the rubber composition 100 parts by weight of the rubber matrix contains 5 to 100 parts by weight of branched polyethylene. The rope core used in the rope core conveyor belt is a steel wire rope core or an aramid rope core.
A conveyor belt having a buffer rubber between a covering rubber and an adhesive rubber, characterized in that the rubber used for the buffer rubber comprises the rubber composition according to any one of claims 1 to 26.
The conveyor belt according to claim 35, wherein at least one layer of the working surface covering rubber and the non-working surface covering rubber comprises a rubber composition, and the rubber composition includes branching per 100 parts by weight of the rubber matrix. 5 to 100 parts by weight of polyethylene.
A rubber tube comprising an inner rubber layer, a reinforcing layer and an outer rubber layer, characterized in that at least one of the inner rubber layer and the outer rubber layer comprises the rubber composition according to any one of claims 1 to 26.
A rubber tube comprising an inner rubber layer, a first reinforcement layer, a middle rubber layer, a second reinforcement layer, and an outer rubber layer from the inside to the outside, characterized in that the rubber used in the middle rubber layer includes any one of claims 1 to 26. The rubber composition.
The hose according to claim 42, characterized in that the rubber used in at least one of the outer rubber layer and the inner rubber layer contains a rubber composition, and the rubber composition contains branched polyethylene 5 per 100 parts by weight of the rubber matrix. ~ 100 parts by weight.
A power transmission belt comprising: a main body having a certain length including a buffer rubber layer and a compression rubber layer, characterized in that the rubber used in at least one of the buffer rubber layer and the compression rubber layer includes any one of claims 1 to 26 Mentioned rubber composition.
A rubber roller characterized in that the rubber used comprises the rubber composition according to any one of claims 1 to 26.
A sole, characterized in that the rubber used comprises the rubber composition according to any one of claims 1 to 26.
A rubber shoe having a midsole, characterized in that the rubber used for the midsole comprises the rubber composition according to any one of claims 1 to 26.