WO2018130186A1 - Rubber composite, processing method, sealing element applying composite, and manufacturing method - Google Patents

Abstract

Disclosed is a rubber composite, a method for processing the rubber composite, a sealing strip comprising the rubber composite, and a manufacturing method for the sealing strip. The rubber composite comprises, in terms of parts by weight, the components of : a rubber substrate 100 parts, a crosslink system 2-20 parts, a reinforcing filler 60-300 parts, a plasticizer 20-170 parts, and a metal oxide 3-25 parts. The rubber substrate comprises in terms of parts by mass: branched polyethylene, the content thereof being a : 0 < a ≤ 100 parts, ethylene propylene monomer rubber, the content thereof being b : 0 ≤ b < 100 parts; and ethylene propylene diene monomer rubber, the content thereof being c : 0 ≤ c < 100 parts. The technical effect of the present invention is the provision of the sealing element of great performance in the resistance against permanent deformation under compression.

Description

Rubber composition and processing method, and sealing member and production method thereof Technical field

The invention belongs to the technical field of rubber, and in particular relates to a rubber composition and a processing method thereof, and to a sealing member using the rubber composition, and a method for producing the same.

Background technique

The application of rubber seals generally requires that the product has good aging resistance and low compression set, so as to obtain long-term reliable sealing. At present, many sealing products are made of ethylene propylene rubber. Compared with the sulfur vulcanization system, the peroxide cross-linking system can obtain a rubber product with better aging resistance and lower compression set, but the mechanical strength of the product obtained by peroxide cross-linking is generally weaker than that of sulfur vulcanized product. This will cause the product to be easily damaged or broken during production and use.

How to improve the aging resistance, mechanical strength and compression set resistance of ethylene propylene rubber at the same time is a 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. Chain length, large steric hindrance, difficulty in radical reaction, resulting in difficulty in crosslinking, affecting processing efficiency and product performance, such as compression set resistance is unsatisfactory.

Therefore, there is a need for a better technical solution to improve the aging resistance of ethylene propylene rubber, and at the same time, it has good physical and mechanical properties and cross-linking performance, and has good compression set resistance.

In addition, the compression set property is also related to the molecular weight distribution of ethylene propylene rubber, and the ethylene propylene rubber having a narrow molecular weight distribution has a relatively low compression set. The molecular weight distribution of ethylene propylene rubber is mostly between 3 and 5, and the highest is 8 to 9. The molecular weight distribution of a small amount of ethylene propylene rubber is close to 2 and convenient for processing, but the cost is high. In theory, the molecular weight distribution of the polymer can be as small as 1, so the material selection of the seal can be further optimized to better achieve the sealing effect. Chinese Patent Application No. 201410200113.6 discloses a polyethylene rubber and a processing method thereof, the specific content of which is a raw material formulation of polyethylene rubber, and a processing method thereof, but it does not disclose the use of a new rubber obtained by using the rubber as a rubber matrix. And a method of making a seal using the new rubber. The formulations disclosed in this patent do not adequately meet the process requirements for seals that use rapid extrusion processing. Moreover, the amount of glue is high and the cost is high.

At present, the advantage of using a narrow molecular weight distribution of branched polyethylene has not been seen, and it has been reported for the preparation of a seal having good compression set resistance.

Summary of the invention

In view of the problems in the prior art, the present invention provides a rubber composition and a processing method thereof, and a sealing member comprising the rubber composition and a production method thereof, which have a branching degree of not less than 50 branches/1000 Carbonized branched polyethylene replaces some or all of the ethylene propylene rubber, and has good processing properties while obtaining a seal with good compression set resistance.

In order to achieve the above object, the present invention adopts the following technical solution: a rubber composition comprising, by weight, a rubber matrix and an essential component, the rubber matrix comprising: a branched polyethylene having a content of 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: 2 to 20 parts of the crosslinking system, based on 100 parts by weight of the rubber matrix, 60-300 parts of reinforcing filler, 20-170 parts of plasticizer, 3-25 parts of metal oxide, wherein the branching degree of branched polyethylene is not less than 50 branches/1000 carbons, and the weight average molecular weight Not less than 50,000, the Mooney viscosity ML (1+4) is not lower than 2 at 125 ° C, and the crosslinking system contains a crosslinking agent and a co-crosslinking agent.

"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 to achieve an unexpected beneficial 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 present invention and the prior art ethylene propylene diene 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 branched polyethylene has a proper amount of secondary branched structure, the cross-linking point of branched polyethylene can be in the main chain during peroxide crosslinking or radiation crosslinking. Produced on carbon, can also be produced on the branched tertiary carbon of the secondary structure, so the rubber network formed by the cross-linking or radiation cross-linking of the branched polyethylene is compared with the ethylene-propylene rubber, and the main chain has The richer CC connection segment length can effectively avoid stress concentration and help to obtain better mechanical properties. On the other hand, better cross-linking ability can effectively increase the cross-linking density, and the molecular weight distribution of the branched polyethylene is close to 2, which is narrower than that of the general ethylene-propylene rubber, so that it is also expected to obtain better compression set resistance.

A further technical solution is that the plasticizer content is from 40 to 135 parts based on 100 parts by weight of the rubber matrix.

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 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) 125 ° C. It is 6 to 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 ethylene propylene diene rubber is b: 0 ≤ b ≤ 90 The branched polyethylene is an ethylene homopolymer having a degree of branching of 70 to 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 is 23 to 101.

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

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

The third monomer of the ethylene propylene diene monomer is preferably a diene monomer, and specifically may be selected from the group consisting of 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, and dicyclopentadiene. Alkene, 1,4-hexadiene, 1,5-hexadiene, 1,4-pentadiene, 2-methyl-1,4-pentadiene, 3-methyl-1,4-hexane Alkene, 4-methyl-1,4-hexadiene, 1,9-decadiene, 5-methylene-2-norbornene, 5-pentylene-2-norbornene, 1,5- Cyclooctadiene, 1,4-cyclooctadiene, and the like. In particular, the ethylene propylene rubber may contain two or more kinds of diene monomers, such as 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene. The functional group of the diene monomer can play the same role as the intrinsic co-crosslinking agent in the peroxide vulcanization, thereby improving 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%.

In a further technical solution, the crosslinking agent comprises at least one of sulfur and a peroxide crosslinking agent, and the peroxide crosslinking agent comprises di-tert-butyl peroxide, dicumyl peroxide, Tert-butyl cumyl peroxide, 1,1-tert-butyl peroxide-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butyl Peroxide) hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl At least one of benzyl-2,5-bis(benzoyl peroxy)hexane, tert-butyl peroxybenzoate, and t-butylperoxy-2-ethylhexyl carbonate.

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, sulfur, and a metal salt of an unsaturated carboxylic acid. The unsaturated carboxylic acid metal salt contains at least one of zinc acrylate, zinc methacrylate, magnesium methacrylate, calcium methacrylate, and aluminum methacrylate. Wherein allyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate A cross-linking agent for radiation sensitization.

A further technical solution is that the crosslinking system further comprises 0 to 3 parts of a vulcanization accelerator based on 100 parts by weight of the rubber matrix, and the vulcanization accelerator comprises 2-thiol benzothiazole and dibenzothiazole disulfide. , tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, zinc di-n-butyldithiocarbamate, N-cyclohexyl-2-benzothiazolyl At least one of sulfenamide, N,N-dicyclohexyl-2-phenylthiazolylsulfenamide, bismaleimide, and ethylenethiourea.

In a further technical solution, the plasticizer comprises at least one of stearic acid, pine tar, motor oil, naphthenic oil, paraffin oil, coumarone resin, RX-80, and paraffin wax. The rational use of plasticizers can increase the flexibility of the compound and the plasticity suitable for process operation. In order to increase the viscosity, it is also preferred to use an adhesion promoter such as pine tar, coumarone, RX-80, liquid polyisobutylene or the like. When producing composite rubber products such as foamed solid composite sealing strips, the rubber compound has a certain viscosity which is favorable for molding processing.

In a further technical solution, the reinforcing filler comprises at least one of carbon black, calcium carbonate, calcined clay, magnesium silicate, aluminum silicate, and magnesium carbonate.

In a further technical solution, the metal oxide comprises at least one of zinc oxide, magnesium oxide, and calcium oxide.

In a further technical solution, the rubber composition further comprises an auxiliary component, which comprises, in parts by weight, 100 parts by weight of the rubber base, comprising: 1 to 3 parts of a stabilizer, and 1 to 10 parts of polyethylene glycol. Parts by weight.

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).

In a further technical solution, the polyethylene glycol comprises at least one of polyethylene glycol having a molecular weight of 2000, 3400, and 4000.

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.

The present invention also provides a method of preparing the above rubber composition, comprising the steps of:

(1) setting the temperature of the internal mixer and the rotation speed of the rotor, and sequentially adding the components other than the crosslinking system in the rubber composition to the internal mixer for mixing; then adding a crosslinking system, and discharging the rubber after mixing;

(2) The rubber compound obtained in (1) is thinly spread on the open mill, and the lower piece is placed and parked;

(3) The rubber compound is filled into the cavity of the mold, heated and pressurized on a flat vulcanizer, and then released to obtain a vulcanized rubber. In order to improve the compression set resistance of the vulcanizate, it is further possible to carry out vulcanization using a two-stage vulcanization process.

The present invention also provides a weather strip, characterized in that the compound used comprises the above rubber composition.

The present invention provides a method of producing a weatherstrip that includes the following steps:

(1) Mixing: The rubber composition is made into a rubber compound in an internal mixer, and the rubber compound is automatically cut into a twin-screw extruder to be extruded into a sheet, and then cooled in a film cooler to mix the rubber. Automatically cut to tray packaging after cooling to room temperature;

(2) Extrusion and vulcanization: The extrusion vulcanization process uses a vacuum extruder. The temperature of the extruder is set at 90-100 °C, the screw temperature is 70-80 °C, and the head pressure should be controlled at 15-20 MPa. Machine speed 25 ~ 30 rev / min, using salt bath vulcanization process, spray section temperature 240 ~ 260 ° C, dipping section temperature 210 ~ 230 ° C, dipping section temperature 210 ~ 230 ° C, transmission speed 35 ~ 45 m /min, cooling section temperature 25 ~ 30 ° C;

(3) Cooling, trimming, cutting, and getting the finished product.

The present invention also provides a foamed solid composite sealing strip, wherein the rubber used in the center portion comprises the above rubber composition.

The present invention also provides a method of producing a foamed solid composite weather strip comprising the following steps:

(1) kneading: mixing the solid rubber and the foaming part in the internal mixer, and after the open on the open mill, the lower piece is cooled and parked;

(2) Composite extrusion and vulcanization: the solid part of the rubber mixture and the foamed part of the vulcanized rubber are co-extruded through the composite machine head, the temperature of the extruder is set to 90 to 100 ° C, and the screw temperature is 70 to 80 ° C. The head pressure should be controlled at 15~20MPa, the extruder speed is 25~30rev/min, the salt bath vulcanization process is adopted, the spray section temperature is 250°C, the dipping wheel section temperature is 220°C, the dipping section temperature is 220°C, the transmission speed At 35 to 45 m/min, the cooling zone temperature is 25 to 30 °C.

(3) Cooling, trimming, cutting, and getting the finished product.

The invention also provides a method for producing a sealing strip, the vulcanization process comprising two vulcanization processes of pre-vulcanization and thermal vulcanization, and the pre-vulcanization may be at least one of radiation pre-vulcanization or microwave pre-vulcanization. Pre-vulcanization can impart a certain strength to the rubber, thereby ensuring that the rubber sealing strip can withstand external force without deformation during rapid continuous processing, and can improve the production efficiency and product quality of the sealing strip, and the radiation sensitization is included in the rubber composition of the present invention. When the functional co-crosslinking agent is used, the radiation pre-vulcanization method is preferred because the radiation pre-vulcanization method has the following advantages compared with the microwave pre-vulcanization method: (1) there is no requirement for the polarity of the formulation or the rubber itself, and it is more suitable for containing branching. The rubber composition of polyethylene; (2) can be completed at normal temperature to avoid the problem of heat thinning and dimensional deformation of the rubber; (3) the degree of crosslinking can be adjusted by controlling the irradiation dose, and the control is convenient. This production method is applicable to both solid sealing strips, foamed sealing strips and foamed solid composite sealing strips.

The present invention also provides a kneading process of the above rubber composition. When the rubber matrix contains ethylene propylene diene monomer and the sulfur is mainly used as a vulcanizing agent of the ethylene propylene diene monomer in the crosslinking system, the following rubber may be used. Mixing steps:

(1) mixing the ethylene-propylene-propylene rubber, sulfur, vulcanization accelerator and the remaining components in the weight ratio of the ethylene-propylene-propylene rubber in the rubber composition into a masterbatch according to a conventional process; The remaining ingredients are also blended into a masterbatch according to conventional techniques.

(2) The two masterbatches are thoroughly mixed into a final rubber in an internal mixer, and then opened on an open mill and then placed in a sheet to be vulcanized.

The above mixing process allows most of the sulfur to remain in the EPDM phase, and a small portion of the sulfur enters the rest of the rubber matrix as a co-crosslinking agent for peroxide vulcanization, thus effectively utilizing various sulfurs. effect.

In the heat vulcanization method for the rubber composition provided by the present invention, a heating tank having a heating method such as hot air, a glass bead fluidized bed, ultra high frequency electromagnetic wave (UHF), steam, and a hot molten salt bath (LCM) may be used. And metal molds. The heating temperature is preferably from 150 to 170 ° C; and the heating time is preferably from 1 to 30 minutes.

In the electron beam radiation vulcanization method for the rubber composition provided by the present invention, the energy of the electron beam is preferably from 0.1 to 10 MeV, and more preferably from 0.3 to 2 MeV. The irradiation is carried out so that the absorbed dose is preferably from 5 to 350 kGy, and more preferably from 5 to 100 kGy.

The solid sealing strip produced by using the rubber composition of the invention and the foamed solid composite sealing strip comprising the rubber composition of the invention can be applied to the automobile industry and the construction industry, in particular, can be used as a hood seal, a door frame seal, and a front wind. Window seal, rear windshield seal, side window seal, sunroof seal, door seal, glass guide seal, trunk seal, back door seal, back door buffer, plenum Cover seals on the cover, building door and window seals, building waterproof seals, etc.

Compared with the prior art, the beneficial effects of the invention are: the molecular structure of the branched polyethylene is similar to that of ethylene propylene rubber, the molecular structure is completely saturated, the aging resistance is excellent, and the molecular weight distribution is generally less than 2.5, most of which is 1.7. Between -2.1, the molecular weight distribution is narrow, and as with ethylene propylene rubber, peroxide vulcanization can be used. Therefore, the branched polyethylene is added as a rubber component to the formulation of the rubber composition. The size or article obtained after vulcanization can have good compression set 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, 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 materials selected for the rubber substrate of the present invention are:

The Mooney viscosity ML (1+4) of the selected ethylene propylene rubber is preferably 30 to 60 at 125 ° C, and the ethylene content is preferably in the range of 40% to 60%.

The Mooney viscosity ML (1+4) 125 ° C of the selected ethylene propylene diene rubber is preferably 20 to 100, more preferably 50 to 80, and the ethylene content is preferably in the range of 50% to 70%, and the third monomer is preferably used. It is 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene or dicyclopentadiene, and the third monomer content is 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 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 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.

The details are as follows:

Unless otherwise stated, the rubber performance test method:

1. Hardness test: According to the national standard GB/T 531.1-2008, the test is carried out with a hardness tester, and the test temperature is room temperature.

2, tensile strength, elongation at break performance test: in accordance with the national standard GB/T528-2009, using an electronic tensile testing machine for testing, the tensile speed is 500mm / min, the test temperature is 23 ± 2 ° C, the sample is type 2 Dumbbell sample.

3. Mooney viscosity test: According to the national standard GB/T1232.1-2000, the test is carried out with a Mooney viscometer. The test temperature is 125 ° C, preheating for 1 minute, and testing for 4 minutes.

4. Compression permanent deformation test: According to the national standard GB/T7759-1996, the test is carried out with a compression permanent deformation device. The B type is compressed at 25% and the test temperature is 70 °C.

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 the following Examples 1 to 12 and Comparative Examples 1 and 2 were as follows: temperature: 170 ° C; pressure: 16 MPa; time was Tc90 + 1 min.

The present invention provides an embodiment of the rubber composition: the rubber composition comprises, by weight, a rubber matrix and an essential component, wherein the rubber matrix comprises: a content of branched polyethylene a: 10 ≤ a ≤ 100 parts ; content of binary ethylene propylene rubber and ethylene propylene diene rubber b: 0 ≤ b ≤ 90 parts; based on 100 parts by weight of the rubber matrix, the necessary components include: 2 to 20 parts of the crosslinking system, reinforcing filler 60 ~ 300 parts, plasticizer 20-170 parts, metal oxide 3-25 parts.

Wherein, the branching degree of the branched polyethylene is 60 to 130 branches/1000 carbons, the weight average molecular weight is 66,000 to 518,000, and the Mooney viscosity ML (1+4) 125 ° C is 6 to 102, wherein The crosslinking system comprises a crosslinking agent and a co-crosslinking agent.

The crosslinking agent provided by the present invention comprises at least one of sulfur or a peroxide crosslinking agent comprising di-tert-butyl peroxide, dicumyl peroxide, and tert-butyl Base peroxide, 1,1-tert-butyl peroxide-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy) Alkane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2, At least one of 5-di(benzoyl peroxide)hexane, tert-butyl peroxybenzoate, and t-butylperoxy-2-ethylhexyl carbonate. 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-indenylene acetonone, 1,2-polybutadiene, sulfur, acrylic acid At least one of zinc, zinc methacrylate, magnesium methacrylate, calcium methacrylate, and aluminum methacrylate. The plasticizer contains at least one of stearic acid, pine tar, motor oil, naphthenic oil, paraffin oil, coumarone resin, RX-80, and paraffin wax. The reinforcing filler contains at least one of carbon black, calcium carbonate, calcined clay, magnesium silicate, aluminum silicate, and magnesium carbonate. The metal oxide contains at least one of zinc oxide, magnesium oxide, and calcium oxide.

The crosslinking system of the present invention further comprises 0 to 3 parts of a vulcanization accelerator, wherein the vulcanization accelerator comprises 2-thiol benzothiazole, dibenzothiazole disulfide, tetramethylthiuram monosulfide, and disulfide tetrasulfide Methyl thiuram, tetraethylthiuram disulfide, zinc di-n-butyldithiocarbamate, N-cyclohexyl-2-benzothiazolyl sulfenamide, N,N-dicyclohexyl-2 At least one of benzothiazole sulfenamide, bismaleimide, and ethylene thiourea.

The rubber composition of the present invention further comprises 1 to 3 parts by weight of a stabilizer and 1 to 10 parts by weight of polyethylene glycol. The stabilizer comprises 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline At least one of porphyrin (AW) and 2-mercaptobenzimidazole (MB). The polyethylene glycol contains at least one of polyethylene glycol having a molecular weight of 2,000, 3,400, and 4,000.

Example 1:

The branched polyethylene used was numbered PER-9.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the internal temperature of the mixer to 80 ° C, the rotor speed to 50 rpm, add 90 parts of ethylene propylene diene rubber and 10 parts of branched polyethylene pre-pressed for 90 seconds; add 10 parts of zinc oxide 1.5 parts of stearic acid, 5 parts of calcium oxide and 3 parts of PEG 3400, mixed for 1 minute;

(2) then adding 120 parts of carbon black N550, 30 parts of calcium carbonate, 90 parts of paraffin oil SUNPAR 2280 to the rubber compound, and kneading for 3 minutes;

(3) Finally, add 4 parts of cross-linking agent dicumyl peroxide (DCP), 1.5 parts of cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur, and mix for 2 minutes. .

(4) 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 for 20 hours.

(5) After the vulcanization, the test was carried out for 16 hours.

Example 2:

The branched polyethylene used was numbered PER-8.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 20 parts of ethylene propylene diene rubber, 50 parts of ethylene propylene diene monomer and 30 parts of prepolymerized polyethylene. 90 seconds; adding 15 parts of zinc oxide, 2 parts of stearic acid, 10 parts of calcium oxide and 3 parts of PEG 3400, mixing for 1 minute;

(2) then adding 120 parts of carbon black N550, 30 parts of calcium carbonate, 80 parts of paraffin oil SUNPAR 2280 to the compound, and kneading for 3 minutes;

(3) Finally, add 4 parts of cross-linking agent dicumyl peroxide (DCP), 1.5 parts of cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur, and mix for 2 minutes. ;

(4) The rubber compound is 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 parked for 20 hours;

(5) After the vulcanization, the test was carried out for 16 hours.

Example 3:

The branched polyethylene used was numbered PER-5.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 50 parts of ethylene propylene diene monomer and 50 parts of branched polyethylene for 90 seconds; add 5 parts of zinc oxide 1.5 parts of stearic acid, 5 parts of calcium oxide and 3 parts of PEG 3400, mixed for 1 minute;

(2) then adding 120 parts of carbon black N550, 30 parts of calcium carbonate, 80 parts of paraffin oil SUNPAR 2280 to the compound, and kneading for 3 minutes;

(3) Finally, add 4 parts of cross-linking agent dicumyl peroxide (DCP), 1.5 parts of cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur, and mix for 2 minutes. ;

(4) The rubber compound is 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 parked for 20 hours;

(5) After the vulcanization, the test was carried out for 16 hours.

Example 4:

The branched polyethylene used was numbered PER-3.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 30 parts of EPDM rubber and 70 parts of branched polyethylene for 90 seconds, and add 5 parts of zinc oxide. 0.5 parts of stearic acid, 5 parts of calcium oxide and 2 parts of PEG 3400, mixed for 1 minute;

(2) Then, 60 parts of carbon black N550, 10 parts of calcium carbonate, 20 parts of paraffin oil SUNPAR 2280 were added to the rubber compound, and kneaded for 3 minutes;

(3) Finally, add 1.4 parts of cross-linking agent dicumyl peroxide (DCP), 0.4 parts of cross-linking agent triallyl isocyanurate (TAIC) and 0.2 parts of sulfur, and mix for 2 minutes. ;

(4) The rubber compound is 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 parked for 20 hours;

(5) After the vulcanization, the test was carried out for 16 hours.

Example 5:

The branched polyethylene used was numbered PER-5.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the mixer to 80 ° C, the rotor speed to 50 rpm, add 100 parts of branched polyethylene pre-pressed and kneaded for 90 seconds; add 5 parts of zinc oxide, 1.5 parts of stearic acid, 5 Part of calcium oxide and 3 parts of PEG3400, mixed for 1 minute;

(2) then adding 120 parts of carbon black N550, 30 parts of calcium carbonate, 80 parts of paraffin oil SUNPAR 2280 to the compound, and kneading for 3 minutes;

(3) Finally, add 4 parts of cross-linking agent dicumyl peroxide (DCP), 1.5 parts of cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur, and mix for 2 minutes. ;

(4) The rubber compound is 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 parked for 20 hours;

(5) After the vulcanization, the test was carried out for 16 hours.

Example 6

The branched polyethylene used was numbered PER-6.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 50 parts of ethylene propylene diene monomer and 50 parts of branched polyethylene for 90 seconds; add 5 parts of zinc oxide 1 part of stearic acid, mixed for 1 minute;

(2) then adding 80 parts of carbon black N550, 10 parts of calcium carbonate, 60 parts of paraffin oil SUNPAR 2280 to the rubber compound, and kneading for 3 minutes;

(3) Finally, add 3 parts of cross-linking agent bis(tert-butylperoxyisopropyl)benzene (BIPB) and 1 part of cross-linking agent triallyl isocyanurate (TAIC), and mix for 2 minutes. Discharge

(4) The rubber compound is 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 parked for 20 hours;

(5) After the vulcanization, the test was carried out for 16 hours.

Example 7

The branched polyethylene used was numbered PER-6.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 100 parts of branched polyethylene pre-pressed and kneaded for 90 seconds; add 5 parts of zinc oxide, 1 part of stearic acid, and mix 1 minute;

(2) then adding 80 parts of carbon black N550, 10 parts of calcium carbonate, 60 parts of paraffin oil SUNPAR 2280 to the rubber compound, and kneading for 3 minutes;

(3) Finally, add 3 parts of cross-linking agent bis(tert-butylperoxyisopropyl)benzene (BIPB) and 1 part of cross-linking agent triallyl isocyanurate (TAIC), and mix for 2 minutes. Discharge the glue.

(4) 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 for 20 hours.

(5) After the vulcanization, the test was carried out for 16 hours.

Example 8

The branched polyethylene used was numbered PER-7.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 30 parts of ethylene propylene diene rubber and 70 parts of branched polyethylene for 90 seconds, and add 3 parts of zinc oxide. 5 parts of calcium oxide and 2 parts of PEG 3400, mixed for 1 minute;

(2) then adding 80 parts of carbon black N550, 10 parts of calcium carbonate, 40 parts of paraffin oil SUNPAR 2280 to the rubber compound, and kneading for 3 minutes;

(3) Finally, add 4 parts of cross-linking agent dicumyl peroxide (DCP), 1 part of cross-linking agent triallyl isocyanurate (TAIC) and 15 parts of cross-linking agent 1,2-poly Butadiene, after 2 minutes of mixing, the glue is discharged;

(4) 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 for 20 hours.

(5) After the vulcanization, the test was carried out for 16 hours.

Example 9

The branched polyethylene used was numbered PER-4.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 70 ° 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 3 parts of zinc oxide Mix with 2 parts of PEG3400 for 1 minute;

(2) Then, 60 parts of carbon black N550 and 20 parts of paraffin oil SUNPAR 2280 were added to the rubber compound, and kneaded for 3 minutes;

(3) Finally, add 1 part of cross-linking agent dicumyl peroxide (DCP), 0.5 part of sulfur, 1 part of tetramethylthiuram disulfide, 1 part of tetramethylthiuram monosulfide and 1 part of two positive Zinc butyl dithiocarbamate, which was kneaded for 2 minutes and then discharged.

(4) 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 for 20 hours.

(5) After the vulcanization, the test was carried out for 16 hours.

Example 10:

The branched polyethylene used was numbered PER-5.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 70 ° 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 10 parts of zinc oxide 3 parts of stearic acid, 7 parts of coumarone resin, 5 parts of calcium oxide and 5 parts of PEG 3400, mixed for 1 minute;

(2) then adding 130 parts of carbon black N550, 70 parts of carbon black N774, 100 parts of calcium carbonate and 160 parts of paraffin oil SUNPAR 2280 to the compound, and kneading for 3 minutes;

(3) Finally, 6 parts of cross-linking agent dicumyl peroxide (DCP) and 2 parts of cross-linking agent triallyl isocyanurate (TAIC) were added, and the mixture was degreased after 2 minutes of mixing;

(4) The rubber compound is 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 parked for 20 hours;

(5) After the vulcanization, the test was carried out for 16 hours.

Example 11

The branched polyethylenes used were numbered PER-2 and PER-8.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 70 ° C, the rotor speed to 50 rpm, add 30 parts of EPDM rubber, 20 parts of PER-2 and 50 parts of PER-8 pre-pressing and kneading for 90 seconds; Add 10 parts of zinc oxide, 2 parts of stearic acid, 3 parts of coumarone resin, 5 parts of calcium oxide and 5 parts of PEG 3400, and knead for 1 minute;

(2) then adding 150 parts of carbon black N550, 80 parts of calcium carbonate and 130 parts of paraffin oil SUNPAR 2280 to the rubber compound, and kneading for 3 minutes;

(3) Finally, 8 parts of cross-linking agent dicumyl peroxide (DCP) and 3 parts of cross-linking agent triallyl isocyanurate (TAIC) were added, and the mixture was drained after 2 minutes of mixing;

(4) 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 for 20 hours.

(5) After the vulcanization, the test was carried out for 16 hours.

Example 12

The branched polyethylene used was numbered PER-1.

The processing steps for testing the rubber composition are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 80 parts of ethylene propylene diene rubber and 20 parts of branched polyethylene for 90 seconds; add 10 parts of zinc oxide 2 parts of stearic acid, 5 parts of calcium oxide and 5 parts of PEG 3400, mixed for 1 minute;

(2) then adding 150 parts of carbon black N550, 80 parts of calcium carbonate and 70 parts of paraffin oil SUNPAR 2280 to the compound, and kneading for 3 minutes;

(3) Finally, 5 parts of cross-linking agent dicumyl peroxide (DCP) and 2 parts of cross-linking agent triallyl isocyanurate (TAIC) were added, and the mixture was drained after 2 minutes of mixing;

(4) The rubber compound is 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 parked for 20 hours;

(5) After the vulcanization, the test was carried out for 16 hours.

Comparative Example 1:

The processing steps of the test rubber composition Comparative Example 1 were as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 100 parts of EPDM rubber for 90 seconds, add 5 parts of zinc oxide, 1.5 parts of stearic acid, 5 parts of calcium oxide and 3 parts of PEG3400, mixed for 1 minute;

(2) then adding 120 parts of carbon black N550, 30 parts of calcium carbonate and 80 parts of paraffin oil SUNPAR 2280 to the rubber compound, mixing for 3 minutes;

(3) Finally, add 4 parts of cross-linking agent dicumyl peroxide (DCP), 1.5 parts of cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur, and mix for 2 minutes. .

(4) 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 for 20 hours.

(5) After the vulcanization, the test was carried out for 16 hours.

Comparative Example 2:

The processing steps of the test rubber composition Comparative Example 2 were as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 100 parts of EPDM rubber for 90 seconds, and add 5 parts of zinc oxide and 1 part of stearic acid. Mix for 1 minute;

(2) then adding 80 parts of carbon black N550, 10 parts of calcium carbonate, 60 parts of paraffin oil SUNPAR 2280 to the rubber compound, and kneading for 3 minutes;

(3) Finally, add 3 parts of cross-linking agent bis(tert-butylperoxyisopropyl)benzene (BIPB) and 1 part of cross-linking agent triallyl isocyanurate (TAIC), and mix for 2 minutes. Discharge

(4) 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 for 20 hours.

(5) After the vulcanization, the test was carried out for 16 hours.

Comparative analysis of test performance data

The rubber obtained by the above examples and the comparative analysis of the rubbers obtained in Comparative Examples 1 and 2, the test performance data are shown in the following table:

Example 13

A sealing strip for automobiles, the production process of which is as follows:

(1) Mixing: The internal temperature of the mixer should be set to 80 ° C, the rotor speed should be 50 rpm, 100 parts of branched polyethylene PER-5 pre-pressed and kneaded for 90 seconds; 5 parts of zinc oxide, 1.5 parts of hard Fatty acid, 5 parts of calcium oxide and 3 parts of PEG3400, kneaded for 1 minute; then add 120 parts of carbon black N550, 30 parts of calcium carbonate, 80 parts of paraffin oil SUNPAR 2280 to the compound, knead for 3 minutes; finally add 4 parts The combined agent dicumyl peroxide (DCP), 1.5 parts of the cross-linking agent triallyl isocyanurate (TAIC) and 0.3 parts of sulfur, after 2 minutes of mixing, the rubber is discharged, and the rubber compound is automatically cut. The film is extruded into a twin-screw extruder, and then cooled in a film cooler. The rubber mixture is cooled down to room temperature and automatically cut into a tray package.

(2) Extrusion and vulcanization: The extrusion vulcanization process uses a vacuum extruder. The temperature of the extruder is set at 90-100 °C, the screw temperature is 70-80 °C, and the head pressure should be controlled at 15-20 MPa. Machine speed 25 ~ 30 rev / min, using salt bath vulcanization process, spray section temperature 250 ° C, dip wheel section temperature 220 ° C, dipping section temperature 220 ° C, transmission speed 35-45 m / min, cooling section temperature 25 to 30 ° C.

(3) Cooling, trimming, cutting, and getting the finished product.

The properties of the tested vulcanizates are as follows:

It can be seen from the performance of the test that the performance of the sealing strip produced by the rubber composition provided by the present invention is superior to that of the sealing strip produced by the prior art.

Example 14

A foamed solid composite sealing strip whose production process is as follows:

(1) rubber mixing: the mixing process of the rubber used in the solid part is the same as in the embodiment 13;

(2) Composite extrusion and vulcanization: the solid part of the rubber mixture and the foamed part of the vulcanized rubber are co-extruded through the composite machine head, the temperature of the extruder is set to 90 to 100 ° C, and the screw temperature is 70 to 80 ° C. The head pressure should be controlled at 15~20MPa, the extruder speed is 25~30rev/min, the salt bath vulcanization process is adopted, the spray section temperature is 250°C, the dipping wheel section temperature is 220°C, the dipping section temperature is 220°C, the transmission speed At 35 to 45 m/min, the cooling zone temperature is 25 to 30 °C.

(3) Cooling, trimming, cutting, and getting the finished product.

Example 15

A sealing strip for automobiles, the production process of which is as follows:

(1) Mixing: The internal temperature of the mixer should be set to 80 ° C, the rotor speed should be 50 rpm, 100 parts of branched polyethylene PER-5 pre-pressed and kneaded for 90 seconds; 5 parts of zinc oxide, 1.5 parts of hard Fatty acid, 5 parts of calcium oxide and 3 parts of PEG3400, kneaded for 1 minute; then add 120 parts of carbon black N550, 30 parts of calcium carbonate, 80 parts of paraffin oil SUNPAR 2280 to the compound, knead for 3 minutes; finally add 4 parts The mixture of dicumyl peroxide (DCP), 1.5 parts of the cross-linking agent trimethylolpropane trimethacrylate and 0.3 parts of sulfur, after 2 minutes of mixing, the rubber is discharged, and the rubber compound is automatically fed to the double The screw extruder extrudes into a sheet, continues to be cooled in the film cooler, and the rubber mixture is cooled down to room temperature and automatically cut into a tray package;

(2) Extrusion and vulcanization: The extrusion vulcanization process uses a vacuum extruder. The temperature of the extruder is set at 50-60 °C, the head pressure should be controlled at 15-20 MPa, and the extruder speed is 30-35 rpm. Minutes, first enter the radiation pre-vulcanization section, the electron beam energy used for irradiation is 1.0MeV, the irradiation dose is 30kGy; then enter the salt bath vulcanization section, the spray section temperature is 250 °C, the dipping section temperature is 220 °C, the immersion section temperature At 220 ° C, the transmission speed is 50 to 60 m / min, and the cooling section temperature is 25 to 30 ° C.

(3) Cooling, trimming, cutting, and getting the finished product.

Example 16:

A sealing strip for automobiles, the production process of which is as follows:

(1) Mixing: The internal temperature of the mixer should be set to 80 ° C, the rotor speed should be 50 rpm, and 70 parts of branched polyethylene PER-10 and 30 parts of EPDM rubber (ML (1+8) 150) were added. °C is 60, ethylene content is 55%, ENB content is 6.5%) pre-pressed and kneaded for 90 seconds; adding 5 parts of zinc oxide, 1 part of stearic acid, 5 parts of calcium oxide and 3 parts of PEG3400, mixing for 1 minute; Add 150 parts of carbon black N550, 80 parts of calcium carbonate, 110 parts of paraffin oil SUNPAR2280, mix for 3 minutes; finally add 4 parts of cross-linking agent dicumyl peroxide (DCP), 1.5 parts of cross-linking agent Trimethylolpropane acrylate and 0.3 parts of sulfur, after 2 minutes of mixing, the rubber is discharged, and the rubber compound is automatically cut into a twin-screw extruder to be extruded into pieces, and then cooled in a film cooler, and the rubber is mixed. Automatically cut to tray packaging after cooling to room temperature;

(2) Extrusion and vulcanization: The extrusion vulcanization process uses a vacuum extruder. The temperature of the extruder is set at 50-60 °C, the head pressure should be controlled at 15-20 MPa, and the extruder speed is 30-35 rpm. Minutes, first enter the radiation pre-vulcanization section, the electron beam energy used for irradiation is 1.0MeV, the irradiation dose is 30kGy; then enter the salt bath vulcanization section, the spray section temperature is 250 °C, the dipping section temperature is 220 °C, the immersion section temperature At 220 ° C, the transmission speed is 50 to 60 m / min, and the cooling section temperature is 25 to 30 ° C.

(3) Cooling, trimming, cutting, and getting the finished product.

Example 17

A sealing strip for automobiles, the production process of which is as follows:

(1) Mixing: The internal temperature of the mixer should be set to 80 ° C, the rotor speed should be 50 rpm, 100 parts of branched polyethylene PER-11 pre-pressed and kneaded for 90 seconds; 5 parts of zinc oxide and 1 part of hard The fatty acid, 3 parts of calcium oxide and 2 parts of PEG3400 were mixed for 1 minute; then 100 parts of carbon black N550, 20 parts of calcium carbonate and 70 parts of paraffin oil SUNPAR 2280 were added to the compound, and kneaded for 3 minutes; finally, 4 parts of the mixture were added. The crosslinking agent DCP, 1 part of the crosslinking agent TAIC and 0.3 parts of sulfur are mixed, the rubber is discharged after 2 minutes of mixing, the rubber compound is automatically discharged into a twin-screw extruder and extruded into a sheet, and the cooling is continued in the film cooler. The rubber compound is cooled down to room temperature and automatically cut into a tray package;

(2) Extrusion and vulcanization: The extrusion vulcanization process uses a vacuum extruder. The temperature of the extruder is set at 90-100 °C, the screw temperature is 70-80 °C, and the head pressure should be controlled at 15-20 MPa. Machine speed 25 ~ 30 rev / min, using salt bath vulcanization process, spray section temperature 250 ° C, dip wheel section temperature 220 ° C, dipping section temperature 220 ° C, transmission speed 35-45 m / min, cooling section temperature 25 to 30 ° C.

(3) Cooling, trimming, cutting, and getting the finished product.

After the test compound of the sealing strip was molded by compression molding, the hardness was 65, the tensile strength was 14.8 MPa, the elongation at break was 537%, and the compression of the B-type sample at 70 ° C × 22 h was measured. The permanent deformation is 8%.

Example 18

A sealing strip for automobiles, the production process of which is as follows:

(1) Mixing: The internal temperature of the mixer should be set to 80 ° C, the rotor speed should be 50 rpm, 100 parts of branched polyethylene PER-11 pre-pressed and kneaded for 90 seconds; 5 parts of zinc oxide and 1 part of hard Fatty acid, 3 parts of calcium oxide and 2 parts of PEG3400, kneaded for 1 minute; then add 120 parts of carbon black N550, 30 parts of calcium carbonate and 80 parts of paraffin oil SUNPAR2280 to the compound, knead for 3 minutes; finally add 4 parts The DCP, 1.5 parts of the cross-linking agent TAIC and 0.3 parts of sulfur are mixed, and the rubber is discharged after 2 minutes of mixing. The rubber compound is automatically discharged into a twin-screw extruder and extruded into a sheet, and then cooled in a film cooler. The rubber compound is cooled down to room temperature and automatically cut into a tray package;

(2) Extrusion and vulcanization: The extrusion vulcanization process uses a vacuum extruder. The temperature of the extruder is set at 90-100 °C, the screw temperature is 70-80 °C, and the head pressure should be controlled at 15-20 MPa. Machine speed 25 ~ 30 rev / min, using salt bath vulcanization process, spray section temperature 250 ° C, dip wheel section temperature 220 ° C, dipping section temperature 220 ° C, transmission speed 35-45 m / min, cooling section temperature 25 to 30 ° C.

(3) Cooling, trimming, cutting, and getting the finished product.

After the test compound of the sealing strip was molded into a test sample by compression molding, the hardness was determined to be 63, the tensile strength was 13.2 MPa, the elongation at break was 387%, and the compression of the B-type sample at 70 ° C × 22 h was measured. The permanent deformation is 6%.

The superiority of the branched polyethylene in cross-linking ability is demonstrated by the cross-linking performance test comparison of Examples 19 and 20 and Comparative Example 3.

The rubber substrate used in Example 19 was 100 parts of PER-12, and the rubber substrate used in Example 20 was 50 parts of PER-12 and 50 parts of ethylene propylene diene monomer (ML (1+4) 125 ° C was 60, and the ethylene content was 68. %, ENB content 4.8%), the rubber substrate used in Comparative Example 3 was 100 parts of the ethylene propylene diene rubber used in Example 20. The rest of the formula is consistent.

The processing steps of the three rubber compositions are as follows:

(1) Mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add the rubber matrix pre-pressing and kneading for 90 seconds; add 5 parts of zinc oxide, 1.5 parts of stearic acid, 2 parts of PEG 4000, 5 Mixing CaO for 1 minute;

(2) then adding 110 parts of carbon black N550, 50 parts of calcium carbonate, 80 parts of paraffin oil to the rubber compound, and kneading for 3 minutes;

(3) Finally, 4 parts of cross-linking agent DCP and 1.5 parts of cross-linking agent TAIC were added, and after 2 minutes of mixing, the glue was discharged;

(4) The rubber compound 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 the vulcanization property was tested after standing for 20 hours;

The test conditions were 175 ° C, 30 min, and the test results were as follows:

	Example 19	Example 20	Comparative Example 3
ML, dN.m	2.07	1.71	1.79
MH, dN.m	16.12	14.82	16.67
MH-ML, dN.m	14.05	13.11	14.88

Tc90,min

5.2

6.2

7.5

The rubber composition of Example 19 has the shortest Tc90, which can be shortened by 30% compared with Comparative Example 3, and the MH-ML value is only lower than that of Comparative Example 3, indicating that the branched polyethylene used in the present embodiment can be excellent in crosslinking ability. The crosslinking ability of conventional EPDM rubber.

Claims (17)

1. A rubber composition comprising: a rubber matrix and an essential component, the rubber matrix comprising: a content of branched polyethylene a: 0 < a ≤ 100 parts; The content of the propylene rubber and the ethylene propylene diene rubber is b: 0 ≤ b < 100 parts; the essential components include: 2 to 20 parts of the crosslinking system, 60 to 300 parts of the reinforcing filler, based on 100 parts by weight of the rubber matrix , plasticizer 20-170 parts, metal oxide 3~25 parts, wherein the branched polyethylene comprises an ethylene homopolymer, the degree of branching is not less than 50 branches / 1000 carbons, and the weight average molecular weight Not less than 50,000, the Mooney viscosity ML (1+4) is not lower than 2 at 125 ° C, and the crosslinking system contains a crosslinking agent and a co-crosslinking agent.
2. The rubber composition according to claim 1, wherein the content of the branched polyethylene is: 10 ≤ a ≤ 100 parts based on 100 parts by weight of the rubber base; the ethylene propylene rubber and the EPDM The content of rubber b: 0 ≤ b ≤ 90 parts, the branched polyethylene is an ethylene homopolymer, the degree of branching is 60 to 130 branches / 1000 carbons, and the weight average molecular weight is 66,000 to 518,000. Mooney viscosity ML (1 + 4) 125 ° C is 6 ~ 102.
3. The rubber composition according to claim 1, wherein the crosslinking agent comprises at least one of a sulfur or a peroxide crosslinking agent, and the peroxide crosslinking agent comprises di-tert-butyl peroxide. , dicumyl peroxide, tert-butyl cumyl peroxide, 1,1-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) At least one of benzene, 2,5-dimethyl-2,5-bis(benzoyl peroxy)hexane, tert-butyl peroxybenzoate, and t-butylperoxy-2-ethylhexyl carbonate One.
4. The rubber composition according to claim 1, wherein 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'-double At least one of a mercaptoacetone, a 1,2-polybutadiene, a sulfur, and a metal salt of an unsaturated carboxylic acid.
5. The rubber composition according to claim 1, wherein the crosslinking system further comprises 0 to 3 parts of a vulcanization accelerator based on 100 parts by weight of the rubber base, and the vulcanization accelerator comprises 2-thiol benzene. And thiazole, dibenzothiazyl disulfide, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, zinc di-n-butyldithiocarbamate, N- At least one of cyclohexyl-2-benzothiazolylsulfenamide, N,N-dicyclohexyl-2-phenylthiazolylsulfenamide, bismaleimide, and ethylenethiourea.
6. The rubber composition according to claim 1, wherein the plasticizer comprises at least at least one of stearic acid, pine tar, motor oil, naphthenic oil, paraffin oil, coumarone resin, RX-80, and paraffin wax. One.
7. The rubber composition according to claim 1, wherein the reinforcing filler comprises at least one of carbon black, calcium carbonate, calcined clay, magnesium silicate, aluminum silicate, and magnesium carbonate.
8. The rubber composition according to claim 1, wherein the metal oxide comprises at least one of zinc oxide, magnesium oxide, and calcium oxide.
9. The rubber composition according to claim 1, wherein the rubber composition further comprises an auxiliary component, which is based on 100 parts by weight of the rubber base, and the auxiliary component comprises, by weight, a stabilizer 1 to 3 Parts, polyethylene glycol 1 to 10 parts.
10. The rubber composition according to claim 9, wherein the stabilizer comprises 2,2,4-trimethyl-1,2-dihydroquinoline (RD), 6-ethoxy- At least one of 2,2,4-trimethyl-1,2-dihydroquinoline (AW) and 2-mercaptobenzimidazole (MB).
11. The rubber composition according to claim 9, wherein the polyethylene glycol comprises at least one of polyethylene glycol having a molecular weight of 2,000, 3,400, and 4,000.
12. A method of processing the rubber composition according to any one of claims 1 to 11, characterized in that the processing method comprises the steps of:

    (1) setting the temperature of the internal mixer and the rotation speed of the rotor, and sequentially adding the components other than the crosslinking system in the rubber composition to the internal mixer for mixing; then adding a crosslinking system, and discharging the rubber after mixing;

    (2) The rubber compound obtained in the step (1) is thinly passed on the open mill, and the lower piece is placed and parked;

    (3) The rubber compound is filled into the cavity of the mold, heated and pressurized on a flat vulcanizer, and then released to obtain a vulcanized rubber.
13. A weather strip comprising the rubber composition according to any one of claims 1 to 11.
14. A method of producing the weather strip of claim 13 comprising the steps of:

    (1) Mixing: The rubber composition is made into a rubber compound in an internal mixer, and the rubber compound is automatically cut into a twin-screw extruder to be extruded into a sheet, and then cooled in a film cooler to mix the rubber. Automatically cut to tray packaging after cooling to room temperature;

    (2) Extrusion and vulcanization: The extrusion vulcanization process uses a vacuum extruder. The temperature of the extruder is set at 90-100 °C, the screw temperature is 70-80 °C, and the head pressure should be controlled at 15-20 MPa. Machine speed 25 ~ 30 rev / min, using salt bath vulcanization process, spray section temperature 240 ~ 260 ° C, dipping section temperature 210 ~ 230 ° C, dipping section temperature 210 ~ 230 ° C, transmission speed 35 ~ 45 m /min, cooling section temperature 25 ~ 30 °C.

    (3) Cooling, trimming, cutting, and getting the finished product.
15. A foamed solid composite sealing strip characterized in that the rubber used in the solid portion comprises the rubber composition according to any one of claims 1 to 11.
16. A method of producing the weather strip of claim 15 comprising the steps of:

    (1) kneading: mixing the solid rubber and the foaming part in the internal mixer, and after the open on the open mill, the lower piece is cooled and parked;

    (2) Composite extrusion and vulcanization: the solid part of the rubber mixture and the foamed part of the vulcanizate are co-extruded through a composite machine head, and then vulcanized by a salt bath vulcanization process;

    (3) After the vulcanization is finished, it is cooled, trimmed, and cut to obtain a finished product.
17. A method of producing a weather strip according to claim 13, wherein the vulcanization process of the production method comprises two processes of pre-vulcanization and thermal vulcanization, and the pre-vulcanization may be at least one of radiation pre-vulcanization or microwave pre-vulcanization. One.