Nylon thermoplastic vulcanized rubber composition, nylon thermoplastic vulcanized rubber and preparation method thereof

Abstract

The invention relates to the field of thermoplastic vulcanized rubber, and discloses a nylon thermoplastic vulcanized rubber composition, nylon thermoplastic vulcanized rubber and a preparation method thereof. The vulcanized rubber composition comprises hydrogenated butadiene-acrylonitrile rubber, nylon, a double-bond-containing acrylic copolymer, a vulcanizing agent and an auxiliary vulcanizing agent, the double-bond-containing acrylic copolymer comprises a structural unit from a compound represented by the following formula (1), a structural unit from an acrylic compound and a structural unit from an acrylate compound, and in the formula (1), the structural unit is selected from a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of a group consisting of R1 is H, alkyl with the carbon atom number of 1-6, halogen or cyano; and R2 is alkylene with the carbon atom number of 1-6. The vulcanized rubber is resistant to abrasion and low temperature, more excellent in mechanical property, environmentally friendly and easy to process, and therefore the defects that a hydrogenated butyronitrile / nylon blending system is poor in two-phase compatibility and insufficient in product comprehensive performance are overcome. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of thermoplastic vulcanized rubber, and in particular to a nylon thermoplastic vulcanized rubber composition, a nylon thermoplastic vulcanized rubber and a preparation method thereof. Background Art

[0002] Hydrogenated nitrile rubber (HNBR) and nylon (PA) are blended and prepared by dynamic vulcanization technology to obtain thermoplastic vulcanizate (TPV) with a continuous "sea-island" structure. Hydrogenated nitrile / nylon thermoplastic vulcanizate maintains the advantages of hydrogenated nitrile rubber and nylon, while the processing fluidity of the rubber is improved, making it have the advantages of good tensile strength, good solvent resistance, good wear resistance, thermoplastic processing, and recyclability. It is suitable for engineering fields related to sealing, impact resistance, friction resistance, tear resistance and other functions, such as aerospace, electronics and electrical, transportation pipelines, automobiles, machinery manufacturing, construction, etc.

[0003] However, due to the thermodynamic incompatibility between nylon and rubber, if the two are directly physically mixed, the resulting composite will have problems such as poor dispersibility and easy phase separation, resulting in poor improvement of the mechanical properties of the material. For this reason, it is necessary to introduce a suitable compatibilizer to act as a "bridge" between components of different polarities in the composite, so that the interfacial bonding between rubber and nylon is enhanced, the two phases are evenly dispersed, and the compatibility is effectively improved.

[0004] On the other hand, the current HNBR composition can only have outstanding performance in one aspect of media resistance, weather resistance, mechanical properties, etc., and it is difficult to meet practical requirements in other aspects. Harsh working environments such as extreme cold, high temperature, high pressure, high friction, strong corrosion, and long working cycles require rubber products to have multiple parallel functions to achieve high performance. It is indeed a big challenge to improve the performance of rubber compounds in multiple aspects at the same time.

[0005] Therefore, it is of great practical significance to further modify and optimize the materials on the basis of increasing the capacity of the rubber plasticizing system and finally obtain thermoplastic vulcanizate with relatively ideal comprehensive performance. Summary of the invention

[0006] The object of the present invention is to provide a nylon thermoplastic vulcanized rubber composition, a nylon thermoplastic vulcanized rubber and a preparation method thereof. The vulcanized rubber of the present invention is not only wear-resistant and low-temperature-resistant, but also has more excellent mechanical properties, and is environmentally friendly and easy to process, thereby overcoming the defects of poor two-phase compatibility of hydrogenated nitrile / nylon blending system and insufficient comprehensive product performance.

[0007] In order to achieve the above object, the present invention provides a nylon thermoplastic vulcanized rubber composition, wherein the vulcanized rubber composition comprises hydrogenated nitrile rubber, nylon, a double-bond acrylic copolymer, a vulcanizing agent and a vulcanizing agent, wherein the double-bond acrylic copolymer has a structural unit derived from a compound represented by the following formula (1), a structural unit derived from an acrylic compound and a structural unit derived from an acrylate compound.

[0008]

[0009] In formula (1), R1 is H, an alkyl group having 1 to 6 carbon atoms, a halogen group or a cyano group; and R2 is an alkylene group having 1 to 6 carbon atoms.

[0010] Preferably, relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the amount of the double bond-containing acrylic copolymer is 4-20 parts by weight, the amount of the vulcanizing agent is 1-12 parts by weight, and the amount of the co-vulcanizing agent is 0.1-6 parts by weight.

[0011] Preferably, relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the amount of the double bond-containing acrylic copolymer is 8-12 parts by weight, the amount of the vulcanizing agent is 3-6 parts by weight, and the amount of the co-vulcanizing agent is 1-3 parts by weight.

[0012] Preferably, the weight ratio of the hydrogenated nitrile rubber to the nylon is 1:0.3-5, preferably 1:0.4-1, and more preferably 1:0.4-0.5.

[0013] Preferably, the composition further contains an auxiliary agent, which is one or more of an antioxidant, a softener, an antioxidant, a lubricant and a stabilizer.

[0014] Preferably, relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the antioxidant, the softener, the antioxidant, the lubricant and the stabilizer are each independently 0.1-4 parts by weight, preferably 0.5-2 parts by weight, and more preferably 0.8-1.2 parts by weight.

[0015] Preferably, the Mooney viscosity ML (1+4) of the hydrogenated nitrile rubber at 100° C. is 20-65.

[0016] Preferably, the hydrogenated nitrile rubber has an acrylonitrile content of 17-42% by weight and a saturation of 85-99%.

[0017] Preferably, the double bond-containing acrylic copolymer has 0.5-5.0 mol% of structural units derived from the compound represented by the above formula (1), 0.1-17.5 mol% of structural units derived from acrylic compounds and 80-99.5 mol% of structural units derived from acrylate compounds; more preferably, the double bond-containing acrylic copolymer has 0.6-4.3 mol% of structural units derived from the compound represented by the above formula (1), 0.6-16.9 mol% of structural units derived from acrylic compounds and 81.5-98.8 mol% of structural units derived from acrylate compounds; further preferably, the double bond-containing acrylic copolymer has 1.7-3.0 mol% of structural units derived from the compound represented by the above formula (1), 7.5-16.9 mol% of structural units derived from acrylic compounds and 85.1-98.8 mol% of structural units derived from acrylate compounds.

[0018] Preferably, the molecular weight distribution of the double bond-containing acrylic copolymer is 1.0-1.8, more preferably 1.3-1.6.

[0019] Preferably, the acrylic compound is selected from one or more acrylic acid or its salts having 3-20 carbon atoms; preferably, the acrylic compound is selected from one or more of acrylic acid, methacrylic acid, sodium acrylate, zinc acrylate, potassium acrylate and magnesium acrylate.

[0020] Preferably, the acrylic acid ester compound is selected from one or more acrylic acid esters having a carbon number of 3-20; more preferably, the acrylic acid ester compound is selected from one or more of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, methyl 2-methacrylate, ethyl 2-methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, isooctyl acrylate, isooctyl methacrylate, dimethylaminoethyl methacrylate, lauryl acrylate, lauryl methacrylate, tetradecyl acrylate and tetradecyl methacrylate.

[0021] A second aspect of the present invention provides a vulcanized rubber, which is obtained by vulcanizing the vulcanized rubber composition according to the first aspect of the present invention.

[0022] The third aspect of the present invention provides a method for preparing a vulcanized rubber, the method comprising: vulcanizing the vulcanized rubber composition described in the first aspect of the present invention.

[0023] Through the above technical scheme, the vulcanized rubber of the present invention is not only wear-resistant and low-temperature-resistant, but also has more excellent mechanical properties, and is environmentally friendly and easy to process, thereby overcoming the defects of poor two-phase compatibility of the hydrogenated nitrile / nylon blend system and insufficient comprehensive product performance. DETAILED DESCRIPTION

[0024] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0025] The first aspect of the present invention provides a vulcanized rubber composition, wherein the vulcanized rubber composition comprises hydrogenated nitrile rubber, nylon, a double-bond-containing acrylic copolymer, a vulcanizing agent and a vulcanizing agent, wherein the double-bond-containing acrylic copolymer has a structural unit derived from a compound represented by the following formula (1), a structural unit derived from an acrylic compound and a structural unit derived from an acrylate compound,

[0026]

[0027] In formula (1), R1 is H, an alkyl group having 1 to 6 carbon atoms, a halogen group or a cyano group; and R2 is an alkylene group having 1 to 6 carbon atoms.

[0028] Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl and n-hexyl groups. Among them, methyl, ethyl and n-propyl groups are preferred, methyl and ethyl groups are more preferred, and methyl groups are particularly preferred.

[0029] Examples of the halogen include fluorine, chlorine, bromine and iodine, preferably fluorine, chlorine or bromine, more preferably chlorine or bromine, and particularly preferably chlorine.

[0030] Examples of the alkylene group having 1 to 6 carbon atoms include methylene, ethylene, n-propylene, n-butylene, n-pentylene and n-hexylene. Among them, methylene, ethylene and n-propylene are preferred, methylene and ethylene are more preferred, and methylene is particularly preferred.

[0031] Preferably, R1 is H, an alkyl group having 1 to 3 carbon atoms, chlorine or cyano; more preferably, R1 is H, methyl, ethyl, propyl, chlorine or cyano; further preferably, R1 is H, methyl or chlorine.

[0032] Preferably, R2 is an alkylene group having 1 to 3 carbon atoms; more preferably, R2 is a methyl group, an ethyl group or a n-propyl group; further preferably, R2 is a methyl group or an ethyl group; particularly preferably, R2 is a methyl group.

[0033] According to the present invention, in order to balance the processing performance and mechanical properties, relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the amount of the double-bond acrylic copolymer is 4-20 parts by weight, the amount of the vulcanizing agent is 1-12 parts by weight, and the amount of the co-vulcanizing agent is 0.1-6 parts by weight; preferably, relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the amount of the double-bond acrylic copolymer is 8-12 parts by weight, the amount of the vulcanizing agent is 3-6 parts by weight, and the amount of the co-vulcanizing agent is 1-3 parts by weight.

[0034] According to the present invention, in order to balance the processing performance and the mechanical properties, the weight ratio of the hydrogenated nitrile rubber to the nylon is 1:0.3-5; preferably, the weight ratio of the hydrogenated nitrile rubber to the nylon is 1:0.4-1; more preferably, the weight ratio of the hydrogenated nitrile rubber to the nylon is more preferably 1:0.4-0.5.

[0035] According to the present invention, in order to obtain better processing performance, preferably, the Mooney viscosity ML (1+4) of the hydrogenated nitrile rubber at 100°C is 20-65; more preferably, the Mooney viscosity ML (1+4) of the hydrogenated nitrile rubber at 100°C is 30-60; further preferably, the Mooney viscosity ML (1+4) of the hydrogenated nitrile rubber at 100°C is 40-60; particularly preferably, the Mooney viscosity ML (1+4) of the hydrogenated nitrile rubber at 100°C is 50-60.

[0036] According to the present invention, preferably, the hydrogenated nitrile rubber has an acrylonitrile content of 17-42% by weight and a saturation of 85-99%; more preferably, the hydrogenated nitrile rubber has an acrylonitrile content of 32-38% by weight and a saturation of 86-92%.

[0037] According to the present invention, in order to obtain better low temperature resistance, preferably, the double bond-containing acrylic copolymer has 0.5-5.0 mol% of structural units derived from the compound represented by the above formula (1), 0.1-17.5 mol% of structural units derived from acrylic compounds and 80-99.5 mol% of structural units derived from acrylate compounds; more preferably, the double bond-containing acrylic copolymer has 0.6-4.3 mol% of structural units derived from the compound represented by the above formula (1), 0.6-16.9 mol% of structural units derived from acrylic compounds and 81.5-98.8 mol% of structural units derived from acrylate compounds; further preferably, the double bond-containing acrylic copolymer has 1.7-3.0 mol% of structural units derived from the compound represented by the above formula (1), 7.5-16.9 mol% of structural units derived from acrylic compounds and 85.1-98.8 mol% of structural units derived from acrylate compounds.

[0038] Preferably, the molecular weight distribution of the double bond-containing acrylic copolymer is 1.0-1.8; more preferably, the molecular weight distribution of the double bond-containing acrylic copolymer is 1.3-1.6.

[0039] According to the present invention, there is no limitation on the nylon, and for example, one or more of nylon 6, nylon 12 and nylon 66 may be used.

[0040] In a preferred embodiment of the present invention, the nylon is nylon 6.

[0041] The acrylic compound is selected from one or more acrylic acid or its salts having 3 to 20 carbon atoms;

[0042] According to the present invention, the acrylic compound can be selected from one or more of acrylic acid, methacrylic acid, sodium acrylate, zinc acrylate, potassium acrylate and magnesium acrylate; preferably, the acrylic compound is selected from one or more of acrylic acid, methacrylic acid, sodium acrylate, zinc acrylate, potassium acrylate and magnesium acrylate.

[0043] According to the present invention, the acrylic acid ester compound is selected from one or more acrylic acid esters having a carbon number of 3-20; more preferably, the acrylic acid ester compound is selected from one or more of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, methyl 2-methacrylate, ethyl 2-methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, isooctyl acrylate, isooctyl methacrylate, dimethylaminoethyl methacrylate, lauryl acrylate, lauryl methacrylate, tetradecyl acrylate and tetradecyl methacrylate.

[0044] According to the present invention, the auxiliary agent may be selected from one or more of antioxidants, softeners, antioxidants, lubricants and stabilizers, and conventional antioxidants, softeners, antioxidants, lubricants and stabilizers in the art may be used without any additional limitation.

[0045] Preferably, relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the antioxidant, the softener, the antioxidant, the lubricant and the stabilizer are each independently 0.5-5 parts by weight; more preferably, the antioxidant, the softener, the antioxidant, the lubricant and the stabilizer are each independently 0.5-2 parts by weight; further preferably, the antioxidant, the softener, the antioxidant, the lubricant and the stabilizer are each independently 0.8-1.2 parts by weight.

[0046] In the present invention, the double bond-containing acrylic copolymer can be obtained by a free radical active polymerization reaction, for example, it can be implemented by ATRP polymerization method (atom transfer radical polymerization), NMP (nitroxide free radical regulated polymerization) polymerization method, and can also be implemented by RAFT (reversible addition-fragmentation chain transfer radical polymerization) polymerization method. In addition to the selection of free radical initiators, other reaction aids can be selected for the active radical polymerization reaction according to the specific implementation method. For example, when the present invention adopts the ATRP polymerization method to prepare the copolymer, the reaction also needs to use a catalyst, that is, the reaction is carried out in the presence of an initiator and a catalyst; when the present invention adopts the RAFT polymerization method to prepare the copolymer, the reaction also needs to use a RAFT agent (CTA), that is, the reaction is carried out in the presence of an initiator and a RAFT agent.

[0047] According to the present invention, the initiator may be any substance commonly used in free radical active polymerization reactions in the art. Preferably, the initiator may be benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN), potassium persulfate, etc. More preferably, the initiator is azobisisobutyronitrile.

[0048] In the present invention, there is no particular limitation on the amount of the initiator, as long as the active free radical polymerization reaction can proceed smoothly. Preferably, the molar ratio of the initiator to the total amount of the monomer components is 1:100-20000, more preferably 1:200-5000.

[0049] According to the present invention, from the aspect of easily obtaining the acrylic copolymer containing double bonds that meets the requirements of the present invention, it is preferred to adopt a RAFT (reversible addition-fragmentation chain transfer radical polymerization) polymerization method. The present invention has no limitation on the RAFT agent used. From the perspective of easy availability of raw materials, the RAFT agent is selected from one or more of cumyl bisthiobenzoate (CDB), benzyl bisthiobenzoate, S-(thiophenyl)acetic acid and its esters, dithiocarboxylic acid esters and benzyl trithiocarbonate.

[0050] Preferably, the molar ratio of the RAFT agent to the total amount of the monomer components is 1:5-1000, more preferably 1:50-200.

[0051] Preferably, the present invention has no particular limitation on the amount of the compound represented by formula (1), the acrylic compound and the acrylic ester compound. Preferably, the molar ratio of the compound represented by formula (1), the acrylic compound and the acrylic ester compound is 0.01-10:0.1-50:100; more preferably, the molar ratio of the compound represented by formula (1), the acrylic compound and the acrylic ester compound is 0.5-4:0.5-12.5:100; further preferably, the molar ratio of the compound represented by formula (1), the acrylic compound and the acrylic ester compound is 0.5-3:5-10:100.

[0052] The conditions for the free radical active polymerization reaction can be appropriately selected according to the specific method used. For example, when the RAFT (reversible addition-fragmentation chain transfer radical polymerization) polymerization method is adopted, the conditions for the free radical polymerization reaction include: temperature of 0-130°C and time of 0.1-10h.

[0053] According to the present invention, in order to reduce costs and increase the processability and compatibility of the obtained copolymer, preferably, the double bond-containing acrylic copolymer also has 0-90 mol% of structural units from a fourth monomer, and the fourth monomer is selected from one or more acrylamide compounds.

[0054] Preferably, the acrylamide compound is selected from one or more of methacrylamide, acrylamide, N-isopropylacrylamide, N-methylacrylamide, N,N-dimethylacrylamide and 2-acrylamide-2-methylpropanesulfonic acid.

[0055] A second aspect of the present invention provides a nylon thermoplastic vulcanizate, wherein the vulcanized rubber is obtained by vulcanizing the vulcanized rubber composition described in the first aspect of the present invention.

[0056] The third aspect of the present invention provides a method for preparing a nylon thermoplastic vulcanizate, wherein the method comprises: a step of vulcanizing the vulcanized rubber composition described in the first aspect of the present invention.

[0057] In a preferred embodiment of the present invention, the method for preparing nylon thermoplastic vulcanizate may include the following steps:

[0058] 1) in the presence of a polar solvent, mixing the hydrogenated nitrile rubber and the double-bond-containing acrylic copolymer to obtain a mixture;

[0059] 2) removing the polar solvent in the mixture obtained in step 1) to obtain a modified hydrogenated nitrile rubber;

[0060] 3) mixing the modified hydrogenated nitrile rubber with one or more selected from an antioxidant, a softener, a lubricant and a stabilizer to obtain a masterbatch;

[0061] 4) melt-plasticizing nylon and an optional antioxidant in an internal mixer to obtain a nylon mixture;

[0062] 5) melt-blending the masterbatch and the nylon mixture in an internal mixer to obtain a mixed material;

[0063] 6) subjecting the mixed material to a first extrusion granulation to obtain mixed granules;

[0064] 7) The mixed pellets are subjected to dynamic vulcanization with a vulcanizing agent and a vulcanizing agent, and then subjected to a second extrusion granulation step.

[0065] In the method for preparing the vulcanized rubber of the present invention, the hydrogenated nitrile rubber and the double-bond-containing acrylic copolymer are as described above and will not be described in detail herein.

[0066] According to the present invention, preferably, in step 1), the polar solvent is first mixed with the hydrogenated nitrile rubber and then secondly mixed with the double bond-containing acrylic copolymer.

[0067] The conditions for the first mixing and the second mixing are not particularly limited, as long as the materials can be fully mixed.

[0068] According to the present invention, the polar solvent is preferably one or more of chloroform, butanone, acetone and tetrahydrofuran.

[0069] Preferably, the amount of the polar solvent is 100-1000 parts by weight, more preferably 500-1000 parts by weight, relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the double-bond-containing acrylic copolymer.

[0070] According to the present invention, preferably, based on the total weight of the hydrogenated nitrile rubber and the double bond-containing acrylic copolymer, the nitrile rubber composite material contains 80-95% by weight of the hydrogenated nitrile rubber, and the amount of the double bond-containing acrylic copolymer is 5-20% by weight; more preferably, based on the total weight of the hydrogenated nitrile rubber and the double bond-containing acrylic copolymer, the nitrile rubber composite material contains 85-90% by weight of the hydrogenated nitrile rubber, and the amount of the double bond-containing acrylic copolymer is 10-15% by weight.

[0071] According to the present invention, in step 2), the method for removing the polar solvent in the mixture obtained in step 1) can adopt various methods commonly used in the art for removing solvents, for example, drying at a temperature of 50-65° C. for 1-3 hours.

[0072] In a preferred embodiment of the present invention, the preparation of the vulcanized rubber can be carried out in equipment commonly used in the art, such as an internal mixer.

[0073] In a preferred embodiment of the present invention, the mixing operation in step 1) is performed by mechanical stirring. There is no particular limitation on the mixing temperature. The mixing can be performed at room temperature. The mixing time is 10-30 minutes; preferably, the mixing time is 15-25 minutes.

[0074] In a preferred embodiment of the present invention, in step 2), the polar solvent can be removed by conventional methods in the art, for example, a vacuum oven can be used to remove the polar solvent, the temperature of the vacuum oven can be set to 50-65° C., and the time can be set to 1-3 hours.

[0075] In a preferred embodiment of the present invention, in step 3), the mixing conditions may include: temperature of 20-40° C. and time of 10-15 min.

[0076] In a preferred embodiment of the present invention, in step 4), the conditions for melt plasticization may include: temperature of 150-200° C. and time of 3-10 min.

[0077] In a preferred embodiment of the present invention, in step 5), the conditions for melt blending may include: temperature of 150-200° C., time of 5-15 min, and internal mixer rotor speed of 50-100 rpm.

[0078] According to the present invention, the first extrusion granulation can be performed in a single screw extruder.

[0079] In a preferred embodiment of the present invention, in step 6), the first extrusion granulation can be carried out in a single screw extruder, and the conditions of the extrusion granulation may include: a temperature of 150-200° C. and a screw speed of 40-220 rpm.

[0080] According to the present invention, the dynamic vulcanization can be carried out in a twin-screw extruder.

[0081] In a preferred embodiment of the present invention, in step 7), the dynamic vulcanization can be carried out in a twin-screw extruder, and the vulcanization conditions may include: a head temperature of 180-200°C, a screw feed section temperature of 120-180°C, a melt mixing section temperature of 180-200°C, a screw speed of 40-220rpm, and a main feeding speed of 25-50rpm.

[0082] According to the present invention, the vulcanizing agent may be any of various agents commonly used for vulcanization in the art, for example, peroxide vulcanizing agent F-40 and the like.

[0083] According to the present invention, the co-vulcanizing agent can use various reagents commonly used for vulcanization in the art, for example, triallyl isocyanurate, etc. According to the present invention, the auxiliary agent can be selected from one or more of an antioxidant, a softener, an antioxidant, a lubricant and a stabilizer.

[0084] According to the present invention, the antioxidant may be various antioxidants commonly used in the field of vulcanization. Specifically, as the antioxidant, for example, antioxidant RD may be used.

[0085] According to the present invention, the softener may be any softener commonly used in the art for vulcanization. Specifically, as the softener, for example, liquid paraffin may be used.

[0086] According to the present invention, the antioxidant may be various antioxidants commonly used in the field of vulcanization. Specifically, as the antioxidant, for example, antioxidant 246 or the like may be used.

[0087] According to the present invention, the lubricant may be various lubricants commonly used in vulcanization in the art. Specifically, as the lubricant, for example, stearic acid may be used.

[0088] According to the present invention, the stabilizer may be various stabilizers commonly used in the field of vulcanization. Specifically, as the stabilizer, for example, barium stearate may be used.

[0089] The present invention will be described in detail below by way of examples, but the present invention is not limited to the following examples.

[0090] In the following examples and comparative examples, unless otherwise specified, the raw materials used are commercially available products.

[0091] In the following examples and comparative examples, "parts" means "parts by weight".

[0092] In the following preparation examples, the content of the structural unit is calculated by the molar amount of the monomer fed and the conversion rate; the number average molecular weight and molecular weight distribution are determined by the GB / T 36214.1-2018 method.

[0093] Preparation Example 1

[0094] In a polymerization bottle, benzyl bisthiobenzoate and azobisisobutyronitrile (AIBN) were dissolved in 50 mL of THF, and allyl acrylate, sodium acrylate and butyl acrylate were added, and the weight percentage concentration of the polymerization monomers in the solvent was 20 wt %; nitrogen was blown for 30 minutes, and the tube was sealed and heated in an oil bath at 60° C. under normal pressure for 6 hours to obtain a copolymer glue solution, and then the copolymer glue solution was subjected to steam condensation and desolventization treatment to obtain copolymer A1.

[0095] The feed ratio of the reactants is: benzyl bisthiobenzoate / AIBN / allyl acrylate / sodium acrylate / butyl acrylate has a molar ratio of 1 / 0.2 / 1 / 1 / 200; after nuclear magnetic resonance measurement, the conversion rates of allyl acrylate and sodium acrylate are 100%, and the conversion rate of butyl acrylate monomer is 80%.

[0096] In copolymer A1, the content of the structural unit derived from allyl acrylate was 0.6 mol %, the content of the structural unit derived from sodium acrylate was 0.6 mol %, the content of the structural unit derived from butyl acrylate was 98.8 mol %, the number average molecular weight was 15200, and PDI was 1.3.

[0097] Preparation Example 2

[0098] In a polymerization bottle, benzyl bisthiobenzoate and azobisisobutyronitrile (AIBN) are dissolved in 50 mL of toluene, and allyl acrylate, acrylic acid and butyl acrylate are added, and the weight percentage concentration of the polymerization monomers in the solvent is 20 weight %; nitrogen gas is blown for 30 minutes, and the tube is sealed and heated in an oil bath at 60°C under normal pressure for 4 hours to obtain a copolymer glue solution, and then the copolymer glue solution is subjected to steam condensation and desolventization treatment to obtain copolymer A2.

[0099] The feed ratio of the reactants is: benzyl bisthiobenzoate / AIBN / allyl acrylate / acrylic acid / butyl acrylate has a molar ratio of 1 / 0.2 / 2 / 5 / 100. According to nuclear magnetic resonance measurement, the conversion rates of allyl acrylate and acrylic acid are 100%, and the conversion rate of butyl acrylate monomer is 60%.

[0100] In copolymer A2, the content of the structural unit derived from allyl acrylate was 3.0 mol%, the content of the structural unit derived from sodium acrylate was 7.5 mol%, the content of the structural unit derived from butyl acrylate was 89.5 mol%, the number average molecular weight was 6100, and PDI was 1.6.

[0101] Preparation Example 3

[0102] In a polymerization bottle, benzyl bisthiobenzoate and azobisisobutyronitrile (AIBN) were dissolved in 50 mL of toluene, and allyl acrylate, methacrylic acid and butyl acrylate were added, and the weight percentage concentration of the polymerization monomers in the solvent was 20 wt %; nitrogen was blown for 30 minutes, and the tube was sealed and heated in an oil bath at 60° C. under normal pressure for 4 hours to obtain a copolymer glue solution, and then the copolymer glue solution was subjected to steam condensation and desolventization treatment to obtain copolymer A3.

[0103] The feed ratio of the reactants is: benzyl bisthiobenzoate / AIBN / allyl acrylate / methacrylic acid / butyl acrylate has a molar ratio of 1 / 0.2 / 5 / 50 / 400; after nuclear magnetic resonance measurement, the conversion rates of allyl acrylate and methacrylic acid are 100%, and the conversion rate of butyl acrylate monomer is 60%.

[0104] In copolymer A3, the content of the structural unit derived from allyl acrylate was 1.7 mol %, the content of the structural unit derived from methacrylic acid was 16.9 mol %, the content of the structural unit derived from butyl acrylate was 81.4 mol %, the number average molecular weight was 41100, and PDI was 1.4.

[0105] Example 1

[0106] The usage of each component is as follows:

[0107] The hydrogenated nitrile rubber is 70 parts by weight, the nylon 6 is 30 parts by weight, the double bond acrylic copolymer is 10 parts by weight, the peroxide vulcanizer F-40 is 5 parts by weight, the co-vulcanizer (triallyl isocyanurate) is 2 parts by weight, the stabilizer barium stearate is 1 part by weight, the antioxidant RD is 1 part by weight, the antioxidant 246 is 1 part by weight, the softener liquid paraffin is 1 part by weight, and the lubricant stearic acid is 1 part by weight.

[0108] In the above formulation, hydrogenated nitrile rubber TH3446 (purchased from LANXESS) was used, with a saturation of 94%, an acrylonitrile content of 34% by weight, and a Mooney viscosity ML (1+4) of 60 at 100°C;

[0109] The solvent is acetone, and the copolymer is double-bond acrylic copolymer A1.

[0110] The reaction steps are as follows:

[0111] 1) 70 parts of hydrogenated nitrile rubber raw rubber were dissolved in 750 parts of solvent to form a rubber solution, and then 10 parts of A1 were mixed with the hydrogenated nitrile rubber solution and subjected to strong mechanical stirring for 20 minutes;

[0112] 2) then drying in a vacuum oven at 53° C. for 2 hours to remove the solvent and obtain a modified hydrogenated nitrile rubber;

[0113] 3) The modified hydrogenated nitrile rubber, the antioxidant, the softener, the lubricant and the stabilizer are mixed in an internal mixer at 30° C. for 10 min to obtain a masterbatch;

[0114] 4) Blending 30 parts of nylon pellets and antioxidant in an internal mixer at 180°C for 3 minutes;

[0115] 5) Then, the masterbatch was added and melt blended at 180° C. and a rotor speed of 80 rpm for 8 minutes;

[0116] 6) granulating and extruding the compounded material at 180° C. and a screw speed of 130 rpm;

[0117] 7) The mixed material, the vulcanizing agent and the co-vulcanizing agent are put into a twin-screw extruder with a die head temperature of 180° C., a screw feed section temperature of 140° C., a melt mixing section temperature of 180° C., a screw speed of 120 rpm, and a main feeding speed of 50 rpm. The raw materials are dynamically vulcanized in the extruder and then extruded and granulated to obtain vulcanized rubber S1.

[0118] Example 2

[0119] Hydrogenated nitrile rubber 4320 (purchased from Ruiong Company) was used, with a saturation of 96%, an acrylonitrile content of 18.6% by weight, and a Mooney viscosity ML (1+4) of 60 at 100°C;

[0120] The solvent is acetone, and the copolymer is double-bond acrylic copolymer A2.

[0121] The composition formula of the remaining raw materials is the same as the preparation process and Example 1 to obtain vulcanized rubber S2.

[0122] Example 3

[0123] Hydrogenated nitrile rubber TH3446 (purchased from LANXESS) was used, with a saturation of 94%, an acrylonitrile content of 34% by weight, and a Mooney viscosity ML (1+4) of 60 at 100°C;

[0124] The solvent is acetone, and the copolymer is double-bond acrylic copolymer A3.

[0125] The composition formula of the remaining raw materials is the same as the preparation process and Example 1, and vulcanized rubber S3 is obtained.

[0126] Example 4

[0127] The weight of hydrogenated nitrile rubber is 40 parts, and the weight of nylon pellets is 60 parts;

[0128] The composition formula of the remaining raw materials is the same as the preparation process and Example 1, and vulcanized rubber S4 is obtained.

[0129] Comparative Example 1

[0130] The composition formula and preparation process of the raw materials are the same as those in Example 1, except that:

[0131] No double bond acrylic copolymers are added;

[0132] Vulcanized rubber D1 was obtained.

[0133] Comparative Example 2

[0134] The composition formula and preparation process of the raw materials are the same as those in Example 1, except that:

[0135] The weight of hydrogenated nitrile rubber is 40 parts, and the weight of nylon pellets is 60 parts;

[0136] No double bond acrylic copolymers are added;

[0137] Vulcanized rubber D2 was obtained.

[0138] Comparative Example 3

[0139] The composition formula and preparation process of the raw materials are the same as those in Example 1, except that:

[0140] No nylon added;

[0141] No double bond acrylic copolymers are added;

[0142] Vulcanized rubber D3 was obtained.

[0143] Test Example 1

[0144] The vulcanized rubber obtained in Examples 1-4 and Comparative Examples 1-3 was tested according to the following method, and the results are shown in Table 1.

[0145] The low temperature resistance of the thermoplastic vulcanizate involved in the examples and comparative examples was tested according to the standard GB / T15256-2014 "Determination of low temperature brittleness of vulcanized rubber or thermoplastic rubber (multiple specimen method)".

[0146] The tensile strength and elongation at break of the vulcanized rubber obtained in the examples and comparative examples were tested according to the standard GB / T528-2009 “Tensile stress test of vulcanized rubber or thermoplastic rubber”.

[0147] The tear strength involved in the examples and comparative examples was tested according to the standard GB / T529-2008 “Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser-shaped, right-angled and crescent-shaped test specimens)”.

[0148] The Shore A hardness involved in the embodiments and comparative examples is tested according to the standard GB / T531.1-2008 "Test method for indentation hardness of vulcanized rubber or thermoplastic rubber Part 1: Shore A durometer method (Shore hardness)".

[0149] The notched impact strength involved in the embodiments and comparative examples was tested according to the standard GB / T1843-2008 “Determination of Izod impact strength of plastics”.

[0150] The compression set involved in the examples and comparative examples was tested according to the standard GB / T7759-1996 “Determination of compression set of vulcanized rubber and thermoplastic rubber at room temperature, high temperature and low temperature”.

[0151] The wear resistance of the thermoplastic vulcanizates involved in the examples and comparative examples was tested according to the standard GBT 1689-2014 “Determination of wear resistance of vulcanized rubber (using Akron abrasion tester)”.

[0152] The test results are shown in Table 1.

[0153] Table 1

[0154] Test items S1 S2 S3 S4 D1 D2 D3 Brittle temperature(℃) -55 -55 -57 -59 -39 -39 -41 Tensile strength(Mpa) 28.7 29.8 33.3 36.0 17.7 19.5 14.6 Elongation at break (%) 377 375 363 350 401 387 480 Tear strength (kN / m) 151 155 162 167 102 132 88 Shore A Hardness 81 80 83 89 68 72 46 Notched impact strength (J / m) 968 979 1058 1164 763 784 756 Compression set (%) 30 31 29 23 52 48 60 Akron wear (%) 84 81 88 74 113 105 120

[0155] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A nylon thermoplastic vulcanized rubber composition, characterized in that: The vulcanized rubber composition comprises hydrogenated nitrile rubber, nylon, a double-bond acrylic copolymer, a vulcanizing agent and a vulcanizing aid, wherein the double-bond acrylic copolymer comprises a structural unit derived from a compound represented by the following formula (1), a structural unit derived from an acrylic compound and a structural unit derived from an acrylate compound. In formula (1), R1 is H, an alkyl group having 1 to 6 carbon atoms, a halogen group or a cyano group; and R2 is an alkylene group having 1 to 6 carbon atoms.

2. The vulcanized rubber composition according to claim 1, wherein The Mooney viscosity ML (1+4) of the hydrogenated nitrile rubber at 100° C. is 20-65.

3. The vulcanized rubber composition according to claim 1, wherein The hydrogenated nitrile rubber has an acrylonitrile content of 17-42% by weight and a saturation of 85-99%.

4. The composition according to any one of claims 1 to 3, wherein Relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the amount of the double-bond acrylic copolymer is 4-20 parts by weight, the amount of the vulcanizing agent is 1-12 parts by weight, and the amount of the co-vulcanizing agent is 0.1-6 parts by weight.

5. The composition according to claim 4, wherein Relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the amount of the double bond-containing acrylic copolymer is 8-12 parts by weight, the amount of the vulcanizing agent is 3-6 parts by weight, and the amount of the co-vulcanizing agent is 1-3 parts by weight.

6. The vulcanized rubber composition according to any one of claims 1 to 3, wherein The weight ratio of the hydrogenated nitrile rubber to the nylon is 1:0.3-5, preferably 1:0.4-1, and more preferably 1:0.4-0.

5.

7. The vulcanized rubber composition according to any one of claims 1 to 3, wherein The composition further contains an auxiliary agent, which is selected from one or more of an antioxidant, a softener, an antioxidant, a lubricant and a stabilizer.

8. The vulcanized rubber composition according to claim 7, wherein: Relative to 100 parts by weight of the total weight of the hydrogenated nitrile rubber and the nylon, the antioxidant, the softener, the antioxidant, the lubricant and the stabilizer are each independently 0.1-4 parts by weight, preferably 0.5-2 parts by weight, and more preferably 0.8-1.2 parts by weight.

9. The vulcanized rubber composition according to any one of claims 1 to 3, wherein The double bond-containing acrylic copolymer has 0.5-5.0 mol% of structural units derived from the compound represented by the above formula (1), 0.1-17.5 mol% of structural units derived from acrylic compounds and 80-99.5 mol% of structural units derived from acrylate compounds; Preferably, the double bond-containing acrylic copolymer has 0.6-4.3 mol% of structural units derived from the compound represented by the above formula (1), 0.6-16.9 mol% of structural units derived from acrylic acid compounds and 81.5-98.8 mol% of structural units derived from acrylate compounds; More preferably, the double bond-containing acrylic copolymer has 1.7-3.0 mol% of structural units derived from the compound represented by the above formula (1), 7.5-16.9 mol% of structural units derived from acrylic compounds and 85.1-98.8 mol% of structural units derived from acrylate compounds.

10. The vulcanized rubber composition according to any one of claims 1 to 3, wherein: The molecular weight distribution of the double bond-containing acrylic copolymer is 1.0-1.8, preferably 1.3-1.

6.

11. The vulcanized rubber composition according to any one of claims 1 to 3, wherein The acrylic compound is selected from one or more acrylic acid or its salts having 3 to 20 carbon atoms; Preferably, the acrylic compound is selected from one or more of acrylic acid, methacrylic acid, sodium acrylate, zinc acrylate, potassium acrylate and magnesium acrylate.

12. The vulcanized rubber composition according to any one of claims 1 to 3, wherein The acrylate compound is selected from one or more acrylates having 3 to 20 carbon atoms; Preferably, the acrylic acid ester compound is selected from one or more of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, methyl 2-methacrylate, ethyl 2-methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, isooctyl acrylate, isooctyl methacrylate, dimethylaminoethyl methacrylate, lauryl acrylate, lauryl methacrylate, myristyl acrylate and myristyl methacrylate.

13. A nylon thermoplastic vulcanizate, characterized in that: The vulcanized rubber is obtained by vulcanizing the vulcanized rubber composition according to any one of claims 1 to 12.

14. A method for preparing nylon thermoplastic vulcanizate, characterized in that: The method comprises the step of vulcanizing the vulcanized rubber composition according to any one of claims 1 to 12.

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