WO2018130200A1

WO2018130200A1 - Rubber composite, processing method, high-strength product applying composite, and manufacturing method

Info

Publication number: WO2018130200A1
Application number: PCT/CN2018/072379
Authority: WO
Inventors: 徐涛; 傅智盛; 吴安洋
Original assignee: 杭州星庐科技有限公司
Priority date: 2017-01-13
Filing date: 2018-01-12
Publication date: 2018-07-19

Abstract

A rubber composite. The rubber composite comprises a rubber substrate and a crosslink system. The rubber substrate comprises the following components in terms of parts by weight: branched polyethylene, the content thereof being a: 0 < a ≤ 100 parts, ethylene propylene monomer rubber, the content thereof being b: 0 ≤ b < 100 parts, ethylene propylene diene monomer rubber, the content thereof being c: 0 ≤ c ≤ 100 parts, and, calculated with the rubber substrate at 100 parts by weight, the crosslink system, the content thereof being d: 1 ≤ d ≤ 15 parts. The crosslink system comprises at least one of a crosslinking agent and a crosslink assisting agent, the degree of branching of the branched polyethylene is no less than 50 branch chains/1000 carbons, the weight-averaged molecular weight is no less than 50 thousand, and the Mooney viscosity is no less than 2 ML(1+4) 125 °C. The rubber composite effectively solves the problem in the prior art of low crosslinking efficiency and mechanical strength and, at the same time, acquires great electrical insulation performance and mechanical strength.

Description

Rubber composition and processing method thereof, and high-strength product and production method using same

Technical field

The present invention relates to the field of rubber, and in particular to a rubber composition and a processing method for obtaining the rubber composition, and to a high-strength rubber product to which the rubber composition is applied, and a method for producing the product.

Background technique

Ethylene-propylene rubber has good electrical insulation properties and has become a widely used insulating material. Ethylene-propylene rubber can be divided into two categories: ethylene-propylene rubber (EPM) and EPDM. Compared with the two, EPM has better electrical insulation and aging resistance, but the vulcanization rate is too slow. The mechanical properties are low; while EPDM has a faster vulcanization rate and higher mechanical properties, but the electrical insulation performance is reduced, so there is a lack of practical applications.

Rubber is also widely used in the preparation of condoms. At present, a large number of condoms and gloves are made of natural rubber, which is easy to age, and natural rubber contains a certain amount of protein, which poses a risk of allergies to the human body.

Both ethylene propylene rubber and EPDM rubber have good aging resistance, but since EPDM rubber contains a third monomer, the molecular chain contains double bonds, and the ethylene propylene rubber molecular chain is completely saturated. Therefore, ethylene propylene rubber has more excellent aging resistance. Therefore, it is common to improve the aging resistance of EPDM by using ethylene propylene rubber in combination. Technical solutions. However, the mechanical strength of the binary ethylene propylene rubber is low, which will affect the overall physical and mechanical properties.

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

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

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

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

Summary of the invention

In view of the problems existing in the prior art, the present invention provides a rubber composition, a processing method and an application thereof, and replaces some or all of the B with a branched polyethylene having a branching degree of not less than 50 branches/1000 carbons. Propylene rubber, using peroxide cross-linking or radiation cross-linking. In one aspect, the rubber composition prepared by the invention has high crosslinking efficiency, electrical insulation and mechanical strength during the crosslinking reaction, and can be used for wire and cable, and on the other hand, the rubber combination prepared by the invention Products such as condoms, gloves, rubber stoppers, medical catheters, etc. can be manufactured by radiation crosslinking or chemical crosslinking processes.

To achieve the above object, the present invention adopts the following technical solutions:

A rubber composition comprising a rubber matrix and a crosslinking system, the rubber matrix comprising the following components, all in parts by weight:

The content of branched polyethylene is a: 0 < a ≤ 100 parts,

The content of the binary ethylene propylene rubber b: 0 ≤ b < 100 parts,

The content of EPDM rubber is c: 0 ≤ c < 100 parts,

The content of the crosslinking system is d: 1 ≤ d ≤ 15 parts, based on 100 parts by weight of the rubber matrix.

The crosslinking system comprises at least one of a crosslinking agent and a co-crosslinking agent, the branching degree of the branched polyethylene is not less than 50 branches/1000 carbons, and the weight average molecular weight is not less than 50,000. , Mooney viscosity ML (1 + 4) 125 ° C is not less than 2.

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

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

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

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

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

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

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

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

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

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

Compared with ethylene-propylene rubber, when the branched polyethylene has an appropriate number of secondary branched structures, the cross-linking point of the branched polyethylene can be in the main chain during peroxide crosslinking or radiation crosslinking. It is produced on the tertiary carbon and can also be produced on the branched tertiary carbon of the secondary structure. Therefore, the rubber network formed by the peroxide crosslinking or radiation crosslinking of the branched polyethylene is compared with the ethylene-propylene rubber between the main chains. With a richer CC link length, it can effectively avoid stress concentration and help to obtain better mechanical properties.

The branched polyethylene is an ethylene homopolymer, preferably 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. It is 23 to 101.

The branched polyethylene is an ethylene homopolymer, preferably 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 of ML (1+4) of 125 ° C. It is 40 to 95.

The branched polyethylene is an ethylene homopolymer, preferably 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 of ML (1+4) of 125 ° C. It is 42 to 80.

The content of the branched polyethylene in the rubber matrix is a: 10 ≤ a ≤ 100 parts, the content of the binary ethylene propylene rubber b: 0 ≤ b ≤ 90 parts, and the content of the EPDM rubber, based on 100 parts by weight c: 0 ≤ c ≤ 90 parts, the branched polyethylene is an ethylene homopolymer, the degree of branching is 60-130 branches / 1000 carbon, the weight average molecular weight is 66,000 ~ 518,000, Mooney viscosity ML (1+4) 125 ° C is 6 to 102.

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. Specifically, the ethylene propylene rubber may contain two or more kinds of diene monomers at the same time, such as 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene. The functional group of the diene monomer can 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%.

The crosslinking agent comprises at least one of a sulfur or a peroxide crosslinking agent,

The peroxide crosslinking agent comprises di-tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, 1,1-di-tert-butyl peroxide-3,3,5 -trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxide) Hexyne-3, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(benzoyl peroxy)hexane, tert-butyl peroxybenzoate, At least one of tert-butylperoxy-2-ethylhexyl carbonate.

The co-crosslinking agent comprises triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, ethyl dimethacrylate, triethylene glycol dimethacrylate , triallyl trimellitate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, N, N'-m-phenylene bismaleimide, N, N'- At least one of bis-indenyl acetonide, 1,2-polybutadiene, and sulfur. Wherein allyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate A cross-linking agent for radiation sensitization.

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, dibenzothiazole disulfide, tetramethyl sulfide Thiuram, tetramethylthiuram disulfide, tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolyl sulfenamide, N,N-dicyclohexyl-2-phenylthiazolyl At least one of sulfenamide, bismaleimide, and ethylene thiourea.

Also included is an auxiliary component, based on 100 parts by weight of the rubber matrix, the auxiliary component comprising the following components, all in parts by weight:

The metal oxide comprises at least one of zinc oxide, magnesium oxide, calcium oxide, lead monoxide, and lead tetraoxide;

The plasticizer comprises at least one of pine tar, motor oil, naphthenic oil, paraffin oil, coumarone, RX-80, stearic acid, paraffin wax; rational use of plasticizer can improve the elasticity and suitability of the rubber compound. Plasticity of process operation. For applications where viscosity is required, in order to increase the viscosity, it is also preferred to use an adhesion promoter such as pine tar, coumarone, RX-80, liquid polyisobutylene and the like.

The colorant comprises at least one of carbon black, titanium white powder, indigo blue, and indigo green;

The inorganic filler comprises at least one of calcium carbonate, talc, calcined clay, magnesium silicate, and magnesium carbonate;

The stabilizer comprises 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6-ethoxy-2,2,4-trimethyl-1,2-di At least one of hydrogenated quinoline (AW) and 2-mercaptobenzimidazole (MB);

The coupling agent comprises vinyl tris(2-methoxyethoxy)silane (A-172), γ-glycidoxypropyltrimethoxysilane (A-187), γ-mercaptopropyltrimethyl At least one of oxysilanes (A-189).

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.

An electric wire comprising a conductor and an insulating layer, the insulating layer comprising the above rubber composition.

The above-mentioned electric wire production method comprises the following process flow: (1) stranded wire; (2) extruded rubber insulating layer; (3) vulcanization; (4) spark high pressure test;

The method for preparing the insulating layer includes the following steps:

Step 1, rubber mixing:

First, the rubber composition components other than the cross-linking system are sequentially added to the internal mixer according to the weight fraction, and then kneaded, and then added to the cross-linking system, uniformly kneaded, and discharged, to obtain a kneaded rubber to be used;

Step 2, continuous extrusion high temperature vulcanization:

The rubber compound obtained in the step 1 is extrusion-coated as an insulating material on an strand by an extruder, and vulcanized by high-temperature steam to form a wire and cable insulation layer.

A cable comprising a conductor, an insulating layer and a jacket layer, at least one of the insulating layer and the jacket layer comprising the rubber composition described above.

The above cable production method comprises the following processes: (1) stranded wire; (2) extruded rubber insulation layer; (3) vulcanization; (4) spark high pressure inspection; (5) cable-forming; (6) extrusion rubber protection Set; (7) vulcanization; (8) printing; (9) to obtain the finished product.

Wherein, the method for preparing the insulating layer or the sheath layer comprises the following steps:

Step 1, rubber mixing:

First, the components of the rubber composition other than the cross-linking system are sequentially added to an internal mixer in terms of parts by weight, and then kneaded, and then added to the cross-linking system, uniformly kneaded, and discharged to obtain a kneaded rubber to be used;

Step 2, continuous extrusion high temperature vulcanization:

The rubber compound obtained in the step 1 is extruded as an insulating material on an strand by an extruder or extruded as a sheath material through an extruder and coated on a cable, and vulcanized by high temperature steam to form a wire and cable. Insulation or jacket layer.

A method for producing a cable, wherein a crosslinking system of a rubber or a sheath layer comprises a radiation sensitizing crosslinking agent, and the production method comprises the following processes: (1) a stranded wire; (2) Extruded rubber insulation layer; (3) radiation vulcanization; (4) spark high pressure test; (5) cable formation; (6) extrusion rubber sheath; (7) radiation vulcanization; (8) printing; (9) .

Step 1, rubber mixing:

First, the rubber composition components other than the cross-linking system are sequentially added to the internal mixer according to the parts by weight for kneading, and then the radiation-sensitized co-crosslinking agent is added and uniformly mixed, and then the mixture is discharged to obtain a mixed rubber for use;

Step 2, continuous extrusion of radiation crosslinks:

The rubber compound obtained in the step 1 is extruded as an insulating material on an strand by an extruder or extruded as a sheath material through an extruder and coated on a cable, and crosslinked by radiation to form a wire and cable. Insulation or jacket layer.

A glove comprising a rubber composition as described above.

The method for producing the above glove comprises the following steps:

(1) Rubber kneading: First, the rubber composition components other than the crosslinking system are sequentially added to an internal mixer in terms of parts by weight, and then kneaded, and then added to a crosslinking system, uniformly kneaded, and discharged to obtain a rubber compound. stand-by;

(2) preparing a latex: after dissolving the mixture in an alkane solvent, emulsification and dispersion to obtain a latex;

(3) The dip molding process is: after the mold is cleaned and dried, the coagulant is dipped, dried, dipped latex, raised, high temperature crosslinked, parked, coated, rolled, demolded, finished, and obtained gloves.

A condom comprising the above rubber composition.

The crosslinking system in the compound used contains a radiation sensitizing co-crosslinking agent.

The method for producing the condom includes the following steps:

(1) Rubber mixing:

First, the rubber composition components other than the cross-linking system are sequentially added to the internal mixer according to the parts by weight for kneading, and then the radiation-sensitized co-crosslinking agent is added and uniformly mixed, and then the mixture is discharged to obtain a kneaded rubber to be used;

(2) Emulsification:

The rubber compound prepared in the step 1 is sufficiently dissolved in an alkane solvent, and then emulsified to remove the solvent to obtain a latex;

(3) Irradiation cross-linking:

After the latex prepared in the step 2 is allowed to stand and dried to form a film, the mixture is irradiated and crosslinked at room temperature and air, crimped, demolded, and finished to obtain a condom.

In the present invention, stearic acid can function as an active agent in a sulfur vulcanized system, can form a soluble salt with a metal oxide, and increase the activation of the metal oxide to the promoter.

The present invention also provides a rubber stopper comprising the above rubber composition.

The rubber plug provided by the invention is suitable for use as a medical rubber stopper.

The present invention also provides a method of producing a rubber stopper using a compression vulcanization process comprising the following steps:

(1) Rubber kneading: First, the rubber composition components other than the cross-linking system are sequentially added to an internal mixer in terms of parts by weight, and kneaded, and then added to the cross-linking system to be uniformly kneaded and discharged. The rubber compound is opened and compressed on an open mill, and then parked for use;

(2) calendering: the rubber compound is calendered on a calender and preformed, and then cooled;

(3) vulcanization: putting the calendered rubber into a mold, performing mold vulcanization, and releasing the mold after a predetermined curing time;

(4) Post-treatment: punching, cleaning and silicidation, obtaining finished products, packaging and storage.

The present invention also provides a method of producing a rubber stopper using an injection vulcanization process comprising the steps of:

(2) Extrusion: the rubber compound is extruded into a strip through an extruder and parked for use;

(3) vulcanization: vulcanizing the extruded rubber by an injection molding vulcanizer;

(4) Post-treatment: punching, cleaning and silicidation, obtaining finished products, packaging and storage. The rubber plug production process provided by the invention may further comprise a coating process, which improves the mechanical lubricity of the rubber plug and improves the long-term stability of the packaged article. The film material used therein may be at least one selected from the group consisting of a polydimethylsiloxane film, a parylene film, an ethylene-tetrafluoroethylene copolymer film, and a polyester film.

The present invention also provides a catheter comprising the above rubber composition.

The catheter provided by the present invention is suitable for use as a medical catheter or a food catheter.

The invention also provides a method for producing the above-mentioned catheter, which is formed by extrusion molding or compression molding, and the vulcanization method is selected from one of molding vulcanization, high temperature steam vulcanization or radiation crosslinking. The molding method is preferably an extrusion molding method, and the high-temperature steam vulcanization process is suitable for a peroxide crosslinking system, and the peroxide is preferably bis(2,4-dichlorobenzoyl peroxide) or 2,5-dimethyl-2 peroxide. , 5-di(tert-butylperoxy)hexane, the peroxide addition form is further preferably a paste, the radiation crosslinking process is suitable for a radiation crosslinking system, and the radiation crosslinking system can reduce the amount of chemical additives, so that The product is more suitable for the medical field or the food field.

Compared with the prior art, the beneficial effects of the present invention are: (1) the rubber composition of the present invention has good aging resistance and crosslinking ability at the same time; (2) the branched polyethylene does not contain diene in the present invention. The third monomer of the class, so the electrical insulation performance is similar to that of ethylene propylene rubber, but has high crosslinking efficiency and mechanical strength during the crosslinking reaction. When the rubber matrix contains branched polyethylene, the rubber composition The invention can effectively solve the problems of crosslinking efficiency and mechanical strength in the prior art, and at the same time obtain good electrical insulation performance and mechanical strength, and is better applied to wire and cable; (3) the coloring agent in the invention has no carbon black or a very small amount. Carbon black, good insulation; (4) The rubber composition prepared by the invention has high mechanical strength and no protein, so there is no risk of allergy, and the condom, glove, and the like can be manufactured by radiation crosslinking or chemical crosslinking process. Rubber plugs, medical catheters and other products are widely used.

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. .

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

The ethylene propylene rubber used has a Mooney viscosity ML (1+4) of preferably 20 to 100 at 125 ° C, an ethylene content of preferably 55% to 75%, and a third monomer of 5-ethylidene-2-norbornene, 5 - Vinyl-2-norbornene or dicyclopentadiene, the third monomer content being from 1% to 7%.

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

The branched polyethylenes involved in the examples are characterized by a branching degree of 60 to 130 branches/1000 carbons, a weight average molecular weight of 66,000 to 518,000, and a Mooney viscosity of ML (1+4) of 125 ° C of 6 ~102. 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 specific parameters of the branched polyethylene used in the following specific examples are shown in Table 1:

Table 1 Specific parameters of branched polyethylene

Unless otherwise specified, the rubber performance test methods in the specific implementation methods and related experiments are as follows:

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: in accordance with the national standard GB/T1232.1-2000, with Mooney viscosity meter for testing, the test temperature is 125 ° C, preheat 1 minute, test 4 minutes;

4, hot air accelerated aging test: in accordance with the national standard GB/T3512-2001, in the heat aging test chamber, the test conditions are 150 ° C × 72h;

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

6, the positive curing time Tc90 test: in accordance with the national standard GB/T16584-1996, in the rotorless vulcanizer, the test temperature is 160 ° C;

Example 1

The branched polyethylene used in this example is numbered PER-9.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed to 50 rpm, add 90 parts of ethylene propylene rubber and 10 parts of branched polyethylene for 90 seconds, and add 5 parts of oxidation. Zinc, 1 part stearic acid, 2 parts of antioxidant RD, kneaded for 30 seconds; then add 100 parts of talc, 20 parts of paraffin oil SUNPAR2280 in the compound, mix for 3 minutes; finally add 3 parts of cross-linking agent peroxidation Diisopropylbenzene (DCP), 1 part of the cross-linking agent, triallyl isocyanurate (TAIC), was mixed for 2 minutes and then discharged. The kneaded rubber was thinly passed on an open mill with a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left for 20 hours;

(2) Vulcanization: vulcanization at 160 ° C, 16 MPa pressure for 30 minutes, and after 16 hours of parking, various tests were carried out.

Example 2

The branched polyethylene used in this example is numbered PER-2.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 60 ° C, the rotor speed to 50 rpm, add 70 parts of ethylene propylene diene rubber and 30 parts of branched polyethylene pre-pressed for 90 seconds; add 5 parts of oxidation Zinc, 1 part stearic acid, 2 parts of antioxidant RD, kneaded for 30 seconds; then add 100 parts of talc, 10 parts of paraffin oil SUNPAR2280 in the compound, mix for 3 minutes; finally add 3 parts of crosslinker DCP, 0.3 parts of sulfur, after 2 minutes of mixing, the glue was discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 40 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left for 20 hours.

Example 3

The branched polyethylene used in this example is numbered PER-4.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor rotation speed is 50 rpm, add 50 parts of ethylene propylene diene rubber and 50 parts of branched polyethylene for pre-pressure mixing for 90 seconds; add 5 parts of oxidation Zinc, 1 part stearic acid, 2 parts of antioxidant RD, kneaded for 30 seconds; then add 100 parts of talc, 20 parts of paraffin oil SUNPAR2280 in the compound, mix for 3 minutes; finally add 3 parts of crosslinker DCP, 1 part of the cross-linking agent TAIC, after 2 minutes of mixing, the glue was discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left for 20 hours.

Example 4

The branched polyethylene used in this example is numbered PER-3.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor rotation speed is 50 rev / min, add 100 parts of branched polyethylene pre-pressure mixing for 90 seconds; add 5 parts of zinc oxide, 1 part of stearic acid, 2 parts of antioxidant RD, mixing for 30 seconds; then add 100 parts of talc, 20 parts of paraffin oil SUNPAR2280 in the compound, mix for 3 minutes; finally add 3 parts of crosslinker DCP, 1 part of cross-linking agent TAIC, Dispense after 2 minutes of mixing. 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.

Example 5

The branched polyethylene used in this example is numbered PER-9.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 100 ° C, the rotor speed is 50 rpm, add 85 parts of EPDM rubber and 15 parts of branched polyethylene for 90 seconds premixing; add 5 parts of oxidation Zinc, 5 parts of lead trioxide, 1 part of stearic acid, 2 parts of antioxidant RD, mixed for 30 seconds; then add 120 parts of talc, 5 parts of coloring agent carbon black N550, 20 parts of paraffin oil SUNPAR2280 , mixing for 3 minutes; finally adding 1.5 parts of sulfur, 1.5 parts of accelerator N-cyclohexyl-2-benzothiazole sulfenamide and 0.4 parts of promoter tetramethylthiuram disulfide, mixing for 2 minutes gum. 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.

(2) Vulcanization: vulcanization at 160 ° C, 16 MPa pressure for 15 minutes, after 16 hours of parking, various tests were carried out.

Example 6

The branched polyethylene used in this example is numbered PER-8.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed is 50 rpm, add 30 parts of ethylene propylene diene rubber, 50 parts of ethylene propylene diene monomer and 20 parts of prepolymerized polyethylene. 90 seconds; add 5 parts of zinc oxide, 1 part of stearic acid, 2 parts of antioxidant RD, mix for 30 seconds; then add 120 parts of talcum powder, 5 parts of coloring agent carbon black N550, 20 parts of paraffin oil SUNPAR 2280, mixing for 3 minutes; finally adding 3 parts of crosslinker DCP, 1 part of cross-linking agent TAIC, and mixing for 2 minutes, and then discharging the glue. 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.

Example 7

The branched polyethylene used in this example is numbered PER-5.

The processing method is as follows:

(1) Rubber 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 10 parts of oxidation Zinc, 1 part stearic acid, 2 parts of antioxidant RD, kneaded for 30 seconds; then add 120 parts of talc, 5 parts of coloring agent carbon black N550, 40 parts of paraffin oil SUNPAR2280, and mix for 3 minutes; finally 1.5 parts of cross-linking agent DCP, 0.3 part of cross-linking agent TAIC were added, and the mixture was kneaded for 2 minutes and then discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left for 20 hours.

Example 8

The branched polyethylene used in this example is numbered PER-6.

The processing method is as follows:

(1) Rubber 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 premixing; add 10 parts of oxidation Zinc, 2 parts stearic acid, 2 parts of antioxidant RD, kneaded for 30 seconds; then add 120 parts of talc, 80 parts of calcined clay, 1 part of vinyl tris(2-methoxyethoxy) to the compound Silane, 5 parts of colorant carbon black N550, 20 parts of paraffin oil SUNPAR2280, mixed for 3 minutes; finally added 5 parts of crosslinker DCP, 2 parts of cross-linking agent TAIC and 8 parts of cross-linking agent 1,2-poly Diene, rubberized after 2 minutes of mixing. 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.

Example 9

The branched polyethylene used in this example is numbered PER-5.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor rotation speed is 50 rev / min, add 100 parts of branched polyethylene pre-pressure mixing for 90 seconds; add 5 parts of zinc oxide, 1 part of stearic acid, 2 parts of antioxidant RD, kneaded for 30 seconds; then add 120 parts of calcined clay, 2 parts of vinyl tris(2-methoxyethoxy)silane, 5 parts of coloring agent carbon black N550, 20 parts of paraffin Oil SUNPAR 2280, kneaded for 3 minutes; finally, add 3 parts of crosslinker DCP, 1 part of cross-linking agent TAIC, and mix for 2 minutes and then drain. 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.

The rubber composition of Examples 1 to 9 is extruded as an insulating material through an extruder to form an insulating layer on a strand, and then enters a vulcanization tank for vulcanization. After product inspection, a wire and cable product is obtained, and then extruded. The rubber sheath is covered, and then the high-temperature vulcanization tube is vulcanized and printed to obtain the finished wire and cable.

Comparative Example 1

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 100 parts of ethylene-propylene rubber pre-pressed and kneaded for 90 seconds; add 5 parts of zinc oxide, 1 part of stearic acid 2 parts of antioxidant RD, mixing for 30 seconds; then add 100 parts of talc, 20 parts of paraffin oil SUNPAR2280 in the compound, mix for 3 minutes; finally add 3 parts of crosslinker DCP, 1 part of cross-linking agent TAIC After 2 minutes of mixing, the glue is discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left for 20 hours.

Comparative Example 2

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed is 50 rpm, add 100 parts of EPDM rubber for 90 seconds, and add 5 parts of zinc oxide and 1 part of stearic acid. 2 parts of anti-aging agent RD, mixing for 30 seconds; then adding 120 parts of talc powder, 5 parts of coloring agent carbon black N550, 20 parts of paraffin oil SUNPAR2280, mixing for 3 minutes; finally adding 3 parts of crosslinker DCP 1 part of the cross-linking agent TAIC, after 2 minutes of mixing, the glue is discharged. The kneaded rubber was thinly passed through an open mill having a roll temperature of 60 ° C to obtain a sheet having a thickness of about 2.5 mm, and was left to stand for 20 hours.

The performance test results of the rubbers of Examples 1-9 and Comparative Examples 1 and 2 are shown in Table 2 below:

Table 2 Performance test results of Examples 1-9 and Comparative Examples 1 and 2

Example 10

The branched polyethylene used in this example is numbered PER-6.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 90 ° C, the rotor rotation speed is 50 rpm, add 100 parts of branched polyethylene pre-pressure mixing for 90 seconds; add 10 parts of zinc oxide, mix for 30 seconds; Add 100 parts of calcined clay, 2 parts of vinyltris(2-methoxyethoxy)silane, 10 parts of paraffin oil SUNPAR2280 to the compound, mix for 3 minutes; finally add 1 part of radiation-assisting crosslinker trimethyl Trimethylolpropane acrylate, kneaded for 2 minutes, and discharged. The rubber compound was thinly passed on an open mill with a roll temperature of 80 ° C, and then pressed into a 0.5 mm thick sheet on a flat plate vulcanizer at 120 ° C for 20 hours;

(2) Cross-linking: Irradiation cross-linking was carried out at room temperature and air. The electron beam energy used for irradiation was 1.0 MeV, the beam intensity was 1.0 mA, and the irradiation dose was 200 kGy. After 96 hours of parking, various tests were carried out.

Example 11

The branched polyethylene used in this example is numbered PER-6.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 90 ° C, the rotor rotation speed is 50 rpm, add 100 parts of branched polyethylene pre-pressure mixing for 90 seconds; add 10 parts of zinc oxide, mix for 30 seconds; Add 100 parts of calcined clay, 2 parts of vinyl tris(2-methoxyethoxy)silane, 10 parts of paraffin oil SUNPAR2280 to the rubber compound, mix for 3 minutes; finally add 6 parts of radiation sensitizer Trimethylolpropane methacrylate, kneaded for 2 minutes, and discharged. The rubber compound was thinly passed through an open mill at a roll temperature of 80 ° C, and then pressed into a 0.5 mm thick sheet on a flat plate vulcanizer at 120 ° C for 20 hours.

(2) Cross-linking: Irradiation cross-linking was carried out at room temperature and air. The electron beam energy used for irradiation was 1.0 MeV, the beam intensity was 1.0 mA, the irradiation dose was 100 kGy, and each test was carried out after 96 hours of parking.

Example 12

The branched polyethylene used in this example is numbered PER-7.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 90 ° C, the rotor rotation speed is 50 rpm, add 100 parts of branched polyethylene pre-pressure mixing for 90 seconds; then add 6 parts of radiation sensitizing co-crosslinking agent Trimethylolpropane methacrylate, kneaded for 3 minutes, degumming, the mixture is fully dissolved in hexane solvent, and then emulsified to remove the solvent to obtain a latex;

(2) Cross-linking: After standing and drying, the film is irradiated and cross-linked at room temperature and air. The electron beam energy used for irradiation is 1.0 MeV, the beam intensity is 1.0 mA, and the irradiation dose is 100 kGy. Various tests were carried out after 96 hours;

The rubber composition in the present embodiment is obtained by kneading, dissolving and emulsifying to obtain a latex, and then being irradiated and vulcanized by being immersed and dried in the latex several times in a specific mold, and then subjected to crimping, demolding, finishing, Electrical examination, packaging, and finally get the finished condom.

Example 13

The branched polyethylene used in this example is numbered PER-7.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 90 ° C, the rotor speed to 50 rpm, add 30 parts of ethylene propylene rubber and 70 parts of branched polyethylene for 90 seconds; then add 6 parts. The radiation sensitizer-supporting cross-linking agent trimethylolpropane trimethacrylate was mixed for 3 minutes and degreased. The rubber compound is sufficiently dissolved in a hexane solvent, and then emulsified to remove the solvent to obtain a latex;

(2) Cross-linking: After standing and drying, the film is irradiated and cross-linked at room temperature and air. The electron beam energy used for irradiation is 1.0 MeV, the beam intensity is 1.0 mA, and the irradiation dose is 100 kGy. Each test was conducted after 96 hours.

Example 14

The branched polyethylene used in this example is numbered PER-7.

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 90 ° C, the rotor speed to 50 rpm, add 50 parts of ethylene propylene rubber and 50 parts of branched polyethylene for 90 seconds; then add 6 parts. The radiation sensitizer-supporting cross-linking agent trimethylolpropane trimethacrylate was mixed for 3 minutes and degreased. The rubber compound is sufficiently dissolved in a hexane solvent, and then emulsified to remove the solvent to obtain a latex;

Comparative Example 3:

The processing method is as follows:

(1) Rubber mixing: set the temperature of the internal mixer to 90 ° C, the rotor speed is 50 rpm, add 100 parts of ethylene propylene rubber pre-compression mixing for 90 seconds; then add 6 parts of radiation sensitizing co-crosslinking agent. Trimethylolpropane trimethyl acrylate, kneaded for 3 minutes, and discharged. The rubber compound was sufficiently dissolved in a hexane solvent, and then emulsified to remove the solvent to obtain a latex.

The performance test results of the rubbers of Examples 10-14 and Comparative Example 3 are shown in Table 3 below:

Table 3 Performance test results of rubbers in Examples 10-14 and Comparative Example 3

Example 15

The electric wire of the embodiment is as follows: first, the strand is twisted, and then the rubber compositions of the embodiments 1 to 9 are extruded as an insulating material through an extruder to form an insulating layer on the strand, and then It enters the vulcanization tank for vulcanization, and after passing the product inspection, a wire product is obtained.

Example 16

This embodiment is a method for producing a cable, and the continuous high-temperature vulcanization manufacturing process is specifically as follows: first, the strand is twisted, and then the rubber compositions of Examples 1 to 9 are used as an insulating material to be extruded and wrapped in an extruder. The insulation layer is formed on the line, and the high-temperature vulcanization tube is vulcanized. After the inspection, the cable is formed, and then the rubber sheath is extruded and then vulcanized into a high-temperature vulcanization tube to be printed to obtain a finished cable product.

Example 17

A condom, the radiation cross-linking manufacturing process is as follows:

First, the rubber composition of Example 12 is kneaded, dissolved, and emulsified to obtain a latex, which is then subjected to irradiation vulcanization after being immersed and dried several times in a latex by a specific mold, and then subjected to crimping, demolding, and Finishing, electric inspection, packaging, and finally get the finished product.

Example 18

A medical rubber stopper, the molding and vulcanization production process comprises the following steps:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor rotation speed is 50 rpm, add 100 parts of branched polyethylene pre-pressure mixing for 90 seconds; add 5 parts of zinc oxide, 1 part of stearic acid mixed Refining for 30 seconds; then adding 100 parts of talc, 10 parts of paraffin oil SUNPAR2280 to the compound, mixing for 3 minutes; finally adding 3 parts of crosslinker bis(tert-butylperoxydiisopropyl)benzene, 1 part of help The cross-linking agent TAIC was mixed for 2 minutes and then discharged. The rubber compound was opened and rolled on an open mill with a roll temperature of 60 ° C, and the mixture was allowed to stand for 20 hours. The rubber compound was opened and compressed on an open mill, and then parked for use;

(3) vulcanization: the calendered rubber is placed in a mold and subjected to mold vulcanization at a temperature of 160 ° C, a pressure of 15 MPa, a time of 25 minutes, and after a predetermined curing time, demoulding cooling; (4) post-treatment: punching Clean the silicidation, obtain the finished product, and package it into the warehouse.

Example 19

A condom whose radiation cross-linking manufacturing process comprises the following steps:

(1) Rubber mixing: set the temperature of the mixer to 90 ° C, the rotor speed is 40 rpm, add 100 parts of branched polyethylene PER-10 pre-pressure mixing for 90 seconds; then add 5 parts of radiation sensitization The mixture is trimethylolpropane trimethacrylate, kneaded for 3 minutes, and the rubber is fully dissolved in a solvent of hexane, and then emulsified to remove the solvent to obtain a latex;

(2) Molding: using a specific mold by several times of dipping and drying in the latex;

(3) cross-linking: irradiation cross-linking at room temperature and air, the electron beam energy used for irradiation is 1.0 MeV, the beam intensity is 1.0 mA, and the irradiation dose is 100 kGy;

(4) Post-treatment: curling, demoulding, finishing, electric inspection, packaging, and finally get the finished condom.

The obtained condom compound had a tensile strength of 28.9 MPa and an elongation at break of 683%.

Example 20

(1) Rubber mixing: set the temperature of the internal mixer to 90 ° C, the rotor speed to 40 rpm, add 100 parts of branched polyethylene PER-12 pre-pressure mixing for 90 seconds; then add 6 parts of radiation sensitization The mixture is trimethylolpropane trimethyl methacrylate, kneaded for 3 minutes, and the rubber is fully dissolved in a solvent of hexane, and then emulsified to remove the solvent to obtain a latex;

(3) Cross-linking: irradiation cross-linking at room temperature and air, the electron beam energy used for irradiation is 1.0 MeV, the beam intensity is 1.0 mA, and the irradiation dose is 120 kGy;

The obtained condom compound had a tensile strength of 30.6 MPa and an elongation at break of 712%.

Example 21

A medical catheter adopting an extrusion molding and high-temperature steam vulcanization production process, which comprises the following steps:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 100 parts of branched polyethylene PER-11 pre-pressing and kneading for 90 seconds; then add 10 parts in the rubber. Color paraffin oil, kneaded for 3 minutes; finally added 5 parts of cross-linking agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (paste, 50% active ingredient), 1 part The cross-linking agent TAIC was mixed and mixed for 2 minutes. The rubber compound was opened on a mill with a roll temperature of 60 ° C and left for 20 hours for use;

(2) Extrusion: the rubber compound is extruded on an extruder, the extruder speed is 50r/min, and the head temperature is 90 °C;

(3) Cross-linking: the extruded rubber is first subjected to high-temperature steam vulcanization at a temperature of 170 ° C for 10 min, and the second-stage vulcanization is at 160 ° C for 4 hours;

(4) Post-treatment: cleaning, obtaining finished products, packaging and storage.

Example 22

A medical catheter adopting an extrusion molding and radiation crosslinking production process, which comprises the following steps:

(1) Rubber mixing: set the temperature of the internal mixer to 80 ° C, the rotor speed to 50 rpm, add 100 parts of branched polyethylene PER-5 pre-pressure mixing for 90 seconds; then add 4 parts of radiation sensitization The mixture was trimethylolpropane trimethyl methacrylate, and the rubber was discharged after 2 minutes of mixing. The rubber compound is opened on a mill with a roll temperature of 60 ° C and left for use;

(3) vulcanization: the extruded rubber compound is irradiated and crosslinked at normal temperature, the electron beam energy used for irradiation is 1.0 MeV, the beam current is 1.0 mA, and the irradiation dose is 120 kGy;

Performance data analysis:

1. Comparing Example 3 and Example 4 with Comparative Example 1, it can be seen that as the specific gravity of the branched polyethylene in the rubber matrix increases, the mechanical strength of the vulcanized rubber is significantly improved, aging resistance and electrical insulation. Performance remains at the same level;

2. Comparing Example 7 and Example 9 with Comparative Example 2, it can be seen that the mechanical strength, electrical insulating properties and aging resistance of the vulcanized rubber are different as the specific gravity of the branched polyethylene in the rubber matrix increases. The degree of improvement.

3. It can be seen from Example 10 and Example 11 that the vulcanized rubber obtained by radiation crosslinking has better electrical insulating properties than the vulcanized rubber obtained by peroxide cross-linking or sulfur cross-linking, and from Examples 12 and 13, 14 and Comparative Example 3, it can be seen that the branched polyethylene also has better mechanical strength than the ethylene-propylene rubber in the radiation crosslinking system, and the measured mechanical strength can be as high as 26.9 MPa, which is close to the natural latex irradiation. The mechanical strength of vulcanization, which at least indicates that branched polyethylene can be used to produce traditional natural latex products such as condoms and gloves through a radiation crosslinking process.

The analysis of the vulcanization performance test data of Examples 23 and 24 and Comparative Example 4 below shows that the branched polyethylene has excellent crosslinking ability.

The rubber substrate used in Example 23 was 100 parts of PER-12, and the rubber substrate used in Example 24 was 50 parts of PER-4 and 50 parts of ethylene propylene diene monomer (ML (1+4) 125 ° C was 60, and the ethylene content was 70. %, ENB content 5%), the rubber substrate used in Comparative Example 3 was 100 parts of the ethylene propylene diene rubber used in Example 24. The rest of the formula is consistent.

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

(1) kneading: setting the temperature of the internal mixer to 80 ° C, the rotor rotation speed is 50 rpm, adding a rubber matrix pre-pressing and kneading for 90 seconds; adding 5 parts of zinc oxide, 1 part of stearic acid, and kneading for 1 minute;

(2) then adding 100 parts of talc and 20 parts of paraffin oil to the compound and kneading for 3 minutes;

(3) Finally, 7 parts of cross-linking agent DCP-40 and 1 part 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 40 ° C to obtain a sheet having a thickness of about 2.5 mm, and the vulcanization performance was tested after standing for 20 hours;

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

	实施例23Example 23	实施例24Example 24	对照例4Comparative Example 4
ML,dN.mML, dN.m	0.810.81	0.720.72	0.680.68
MH,dN.mMH, dN.m	13.1413.14	13.2413.24	13.3613.36
MH-ML,dN.mMH-ML, dN.m	12.3312.33	12.5212.52	12.6812.68
Tc90,minTc90,min	5.45.4	6.26.2	6.86.8

The rubber composition of Example 23 had the shortest Tc90, which was nearly 20% shorter than the Tc90 of Comparative Example 3, and the MH-ML value was close to that of Comparative Example 3, indicating that the crosslinking density was close, and the branched polyethylene used in the present invention could be initially indicated. It is close to or even superior to conventional EPDM in cross-linking ability.

While the invention has been described with respect to the embodiments of the present invention, it will be understood by those skilled in the art that the invention may be modified or modified without departing from the spirit and scope of the invention. Modifications and improvements are within the spirit and scope of the invention.

Claims

A rubber composition comprising a rubber matrix and a crosslinking system, the rubber matrix comprising the following components, all in parts by weight:

The content of branched polyethylene is a: 0 < a ≤ 100 parts,

The content of the binary ethylene propylene rubber b: 0 ≤ b < 100 parts,

The content of EPDM rubber is c: 0 ≤ c < 100 parts,

The content of the crosslinking system is d: 1 ≤ d ≤ 15 parts, based on 100 parts by weight of the rubber matrix.

The crosslinking system comprises at least one of a crosslinking agent and a co-crosslinking agent, the branched polyethylene comprising an ethylene homopolymer having a degree of branching of not less than 50 branches/1000 carbons, and an average weight The molecular weight is not less than 50,000, and the Mooney viscosity ML (1+4) is not lower than 2 at 125 °C.
The rubber composition according to claim 1, wherein 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 b: 0 ≤ B≤90 parts; the content of ethylene propylene diene rubber c: 0 ≤ c ≤ 90 parts, the branched polyethylene is an ethylene homopolymer, the degree of branching is 60 to 130 branches / 1000 carbon, heavy The average molecular weight 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 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-di-tert-butyl peroxide-3,3,5-trimethylcyclohexane, 2,5-dimethyl -2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, bis(tert-butylperoxyperoxide) Of phenyl, 2,5-dimethyl-2,5-bis(benzoyl peroxy)hexane, tert-butyl peroxybenzoate, t-butylperoxy-2-ethylhexyl carbonate At least one.
The rubber composition according to claim 1, wherein the co-crosslinking agent comprises triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, Ethyl dimethacrylate, triethylene glycol dimethacrylate, triallyl trimellitate, trimethylolpropane trimethacrylate, N,N'-m-phenylene bismaleimide At least one of N, N'-bis-indenyl acetonone, 1,2-polybutadiene, and sulfur.
The rubber composition according to claim 1, wherein the crosslinking system further comprises 0 to 3 parts of a vulcanization accelerator, and the vulcanization accelerator comprises 2-thiol benzene, based on 100 parts by weight of the rubber base. And thiazole, dibenzothiazyl disulfide, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolyl sulfene At least one of an amide, N,N-dicyclohexyl-2-phenylthiazolylsulfenamide, bismaleimide, and ethylenethiourea.
The rubber composition according to claim 1, wherein the rubber composition further comprises an auxiliary component in an amount of 100 parts by weight of the rubber base, the auxiliary component comprising the following components, all in parts by weight:
The rubber composition according to claim 6, wherein the metal oxide comprises at least one of zinc oxide, magnesium oxide, calcium oxide, lead monoxide, and lead tetraoxide;

The plasticizer comprises at least one of pine tar, motor oil, naphthenic oil, paraffin oil, coumarone, RX-80, stearic acid, and paraffin;

The colorant comprises at least one of carbon black, titanium white powder, indigo blue, and indigo green;

The inorganic filler comprises at least one of calcium carbonate, talc, calcined clay, magnesium silicate, and magnesium carbonate;

The stabilizer comprises 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6-ethoxy-2,2,4-trimethyl-1,2-di At least one of hydrogenated quinoline (AW) and 2-mercaptobenzimidazole (MB);

The coupling agent comprises vinyl tris(2-methoxyethoxy)silane (A-172), γ-glycidoxypropyltrimethoxysilane (A-187), γ-mercaptopropyltrimethyl At least one of oxysilanes (A-189).
An electric wire comprising a conductor and an insulating layer, the insulating layer comprising the rubber composition according to any one of claims 1 to 7.
A method of producing the electric wire according to claim 8, characterized in that the production method comprises the following process flow: (1) stranded wire; (2) extruded rubber insulation layer; (3) vulcanization; (4) spark high pressure test;

Wherein, the processing method for extruding the rubber insulation layer comprises the following steps:

Step 1, rubber mixing:

First, the rubber composition components other than the cross-linking system are sequentially added to the internal mixer according to the weight fraction, and then kneaded, and then added to the cross-linking system, uniformly kneaded, and discharged, to obtain a kneaded rubber to be used;

Step 2, continuous extrusion high temperature vulcanization:

The rubber compound obtained in the step 1 is extrusion-coated as an insulating material on an strand by an extruder, and vulcanized by high-temperature steam to form a wire and cable insulation layer.
A cable comprising a conductor, an insulating layer and a jacket layer, characterized in that at least one of the insulating layer and the sheath layer comprises the rubber composition of any of claims 1-7.
A method of producing the cable of claim 10, characterized in that the production method comprises the following process flow: (1) stranded wire; (2) extruded rubber insulation layer; (3) vulcanization; (4) spark high pressure Inspection; (5) cable-forming; (6) extrusion rubber sheath; (7) vulcanization; (8) printing; (9) obtaining the finished product;

Wherein, the processing method of the insulating layer or the sheath layer comprises the following steps:

Step 1, rubber mixing:

First, the rubber composition components other than the cross-linking system are sequentially added to the internal mixer according to the weight fraction, and then kneaded, and then added to the cross-linking system, uniformly kneaded, and discharged, to obtain a kneaded rubber to be used;

Step 2, continuous extrusion high temperature vulcanization:

The rubber compound obtained in the step 1 is extruded as an insulating material on an strand by an extruder or extruded as a sheath material through an extruder and coated on a cable, and vulcanized by high temperature steam to form a wire and cable. Insulation or jacket layer.
A method for producing a cable according to claim 10, characterized in that the crosslinking system of the rubber or the sheath layer of the cable comprises a radiation sensitizing co-crosslinking agent, and the production method comprises the following process flow: (1) stranded wire; (2) extruded rubber insulation layer; (3) radiation vulcanization; (4) spark high pressure test; (5) cabled; (6) extruded rubber sheath; (7) radiation vulcanization; 8) printing; (9) obtaining the finished product;

Wherein, the processing method of the insulating layer or the sheath layer comprises the following steps:

Step 1, rubber mixing:

First, the rubber composition components other than the cross-linking system are sequentially added to the internal mixer according to the parts by weight for kneading, and then the radiation-sensitized co-crosslinking agent is added and uniformly mixed, and then the mixture is discharged to obtain a mixed rubber for use;

Step 2, continuous extrusion of radiation crosslinks:

The rubber compound obtained in the step 1 is extruded as an insulating material on an strand by an extruder or extruded as a sheath material through an extruder and coated on a cable, and crosslinked by radiation to form a wire and cable. Insulation or jacket layer.
A glove comprising the rubber composition according to any one of claims 1 to 7.
A method of producing the glove of claim 13 wherein the production process comprises the steps of:

(1) Rubber kneading: First, the rubber composition components other than the crosslinking system are sequentially added to an internal mixer in terms of parts by weight, and then kneaded, and then added to a crosslinking system, uniformly kneaded, and discharged to obtain a rubber compound. stand-by;

(2) preparing a latex: after dissolving the mixture in an alkane solvent, emulsification and dispersion to obtain a latex;

(3) The dip molding process is: after the mold is cleaned and dried, the coagulant is dipped, dried, dipped latex, raised, high temperature crosslinked, parked, coated, rolled, demolded, finished, and obtained gloves.
A condom comprising the rubber composition according to any one of claims 1 to 7.
A condom according to claim 15 wherein the crosslinking system in the size used comprises a radiation sensitizing co-crosslinking agent.
The condom according to claim 16, wherein the method of producing the condom comprises the steps of:

(1) Rubber mixing:

First, the rubber composition components other than the cross-linking system are sequentially added to the internal mixer according to the parts by weight for kneading, and then the radiation-sensitized co-crosslinking agent is added and uniformly mixed, and then the mixture is discharged to obtain a kneaded rubber to be used;

(2) Emulsification:

The rubber compound obtained in (1) is sufficiently dissolved in an alkane solvent, and then emulsified to remove the solvent to obtain a latex;

(3) Irradiation cross-linking:

The latex obtained in (2) is allowed to stand still and dried to form a film, and then irradiated and crosslinked at room temperature and air, crimped, demolded, and finished to obtain a condom.
A rubber stopper comprising the rubber composition according to any one of claims 1 to 7.
A method of producing the rubber stopper of claim 18, comprising the steps of:

(1) Rubber kneading: First, the rubber composition components other than the cross-linking system are sequentially added to an internal mixer in terms of parts by weight, and kneaded, and then added to the cross-linking system to be uniformly kneaded and discharged. The rubber compound is opened and compressed on an open mill, and then parked for use;

(2) calendering: the rubber compound is calendered on a calender and preformed, and then cooled;

(3) vulcanization: the calendered rubber is placed in a mold, subjected to mold vulcanization, and after a predetermined sulfurization time, demolding is cooled;

(4) Post-treatment: punching, cleaning and silicidation, obtaining finished products, packaging and storage.
A method of producing the rubber stopper of claim 18, comprising the steps of:

(1) Rubber kneading: First, the rubber composition components other than the cross-linking system are sequentially added to an internal mixer in terms of parts by weight, and kneaded, and then added to the cross-linking system to be uniformly kneaded and discharged. The rubber compound is opened and compressed on an open mill, and then parked for use;

(2) Extrusion: the rubber compound is extruded into a strip through an extruder and parked for use;

(3) vulcanization: vulcanizing the extruded rubber by an injection molding vulcanizer;

(4) Post-treatment: punching, cleaning and silicidation, obtaining finished products, packaging and storage.
A catheter characterized in that the compound used comprises the rubber composition according to any one of claims 1 to 7, and the catheter is a medical catheter or a food tube.
A method of producing the catheter according to claim 21, wherein the production method comprises a molding method and an extrusion molding method, and the molding method is extrusion molding or compression molding, and the curing method is selected from the group consisting of molding vulcanization and high temperature steam. One of vulcanization or radiation crosslinking.