A high temperature resistant hydraulic hose and preparation method thereof

Abstract

The present invention relates to the technical field of rubber tubes, and proposes a high temperature resistant hydraulic hose and a preparation method thereof. The hydraulic hose comprises an inner rubber layer, a reinforcing layer and an outer rubber layer arranged in sequence from the inside to the outside, and the raw materials of the outer rubber layer comprise the following components in parts by weight: 100 parts of chloroprene rubber, 40-60 parts of ethylene-vinyl alcohol copolymer, 20-30 parts of modified nano-alumina, 20-30 parts of carbon black, 0.5-1 part of m-phenylenediamine, 3-5 parts of vulcanizing agent, and 2-4 parts of antioxidant; the raw materials of the modified nano-alumina comprise a modifier and nano-alumina in a weight ratio of 1-9:99; the modifier comprises epoxidized natural rubber. Through the above technical scheme, the problem of poor high temperature resistance of the outer rubber layer of the hydraulic hose in the related art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of rubber tubes, and in particular to a high-temperature resistant hydraulic hose and a preparation method thereof. Background Art

[0002] Hydraulic hose is a rubber hose mainly used to transport liquid media such as hydraulic oil, fuel and lubricating oil. It plays a key role in many industrial fields such as hydraulic systems. Hydraulic hose consists of an inner rubber layer, a reinforcement layer and an outer rubber layer, among which the outer rubber layer mainly plays a role in protecting the internal structure.

[0003] With the rapid development of modern industry, the application scope of hydraulic systems in many fields is constantly expanding and the operating environment is becoming increasingly complex. In many industries, hydraulic equipment often needs to work continuously in high temperature environments, which requires the outer layer of hydraulic hoses to have good high temperature resistance. However, at present, the high temperature resistance of the outer layer of hydraulic hoses still has certain limitations. Therefore, in order to avoid equipment failure caused by high temperature aging of the outer layer, it is of great significance to develop a hydraulic hose with good high temperature resistance of the outer layer. Summary of the invention

[0004] The invention provides a high temperature resistant hydraulic hose and a preparation method thereof, which solves the problem that the outer rubber layer of the hydraulic hose in the related art has poor high temperature resistance.

[0005] The technical solution of the present invention is as follows:

[0006] The present invention provides a high temperature resistant hydraulic hose, comprising an inner rubber layer, a reinforcement layer and an outer rubber layer which are sequentially arranged from the inside to the outside, wherein the raw materials of the outer rubber layer comprise the following components in parts by weight: 100 parts of chloroprene rubber, 40-60 parts of ethylene-vinyl alcohol copolymer, 20-30 parts of modified nano-alumina, 20-30 parts of carbon black, 0.5-1 parts of metaphenylenediamine, 3-5 parts of vulcanizing agent, and 2-4 parts of antioxidant;

[0007] The raw materials of the modified nano-alumina include a modifier and nano-alumina in a weight ratio of 1 to 9:99;

[0008] The modifier includes epoxidized natural rubber.

[0009] As a further technical solution, the raw materials of the inner rubber layer include the following components in parts by weight: 100 parts of nitrile rubber, 20-40 parts of natural rubber, 20-30 parts of carbon black, 3-5 parts of calcium stearate, and 1-3 parts of sulfur.

[0010] In the present invention, the inner rubber layer has good sealing and buffering properties, and can better protect the conveying medium.

[0011] As a further technical solution, the reinforcement layer is a steel wire reinforcement layer.

[0012] In the present invention, the steel wire reinforcement layer can improve the overall pressure resistance of the hydraulic hose, prevent the hydraulic hose from rupturing due to excessive expansion under high pressure, and ensure that the hydraulic hose safely and stably transports hydraulic medium. The steel wire material of the steel wire reinforcement layer can be stainless steel wire, preferably 321 stainless steel wire.

[0013] As a further technical solution, the vulcanizing agent includes one or more of the vulcanizing agent DCP, the vulcanizing agent DBPH, and the vulcanizing agent DTBP.

[0014] In the present invention, the vulcanizing agent is a peroxide vulcanizing agent, which can provide an efficient vulcanization reaction to ensure that the outer rubber layer forms a cross-linked structure, and is preferably a vulcanizing agent DCP.

[0015] As a further technical solution, the antioxidant includes one or more of antioxidant 264, antioxidant 168, and antioxidant 2246.

[0016] In the present invention, the addition of the antioxidant can delay the aging process of the outer rubber layer, thereby extending the service life of the hydraulic hose.

[0017] As a further technical solution, the melt mass flow rate of the ethylene-vinyl alcohol copolymer at 190° C. and 2.16 kg is ≥5.7 g / 10 min.

[0018] In the present invention, when the melt mass flow rate of the ethylene-vinyl alcohol copolymer at 190° C. and 2.16 kg is ≥5.7 g / 10 min, it helps to further improve the high temperature resistance of the outer rubber layer of the hydraulic hose.

[0019] As a further technical solution, the preparation method of the modified nano-alumina comprises the following steps: melting the epoxidized natural rubber, adding the nano-alumina, dispersing evenly, and cooling to obtain the modified nano-alumina.

[0020] As a further technical solution, the median particle size of the nano-alumina is 50-100 nm.

[0021] As a further technical solution, during the melting, the temperature is 160-180°C.

[0022] As a further technical solution, the modifier also includes 4-phenylbenzoic acid, and the weight ratio of the 4-phenylbenzoic acid to the epoxidized natural rubber is 1:2-8.

[0023] In the present invention, the inventors found that when the modifier also includes 4-phenylbenzoic acid, the high temperature resistance of the outer rubber layer of the hydraulic hose can be further improved. It is speculated that 4-phenylbenzoic acid can play a bridging role, improve the modification effect of epoxidized natural rubber on nano-alumina, and thus further improve the high temperature resistance of the outer rubber layer of the hydraulic hose.

[0024] As a further technical solution, the weight ratio of the 4-phenylbenzoic acid to the epoxidized natural rubber is 1:5-8.

[0025] In the present invention, when the weight ratio of 4-phenylbenzoic acid to epoxidized natural rubber is 1:5-8, it helps to further improve the high temperature resistance of the outer rubber layer of the hydraulic hose.

[0026] The present invention also provides a method for preparing a high temperature resistant hydraulic hose, comprising the following steps:

[0027] S1. Evenly mix the components except the vulcanizing agent in the outer rubber layer raw material, add the vulcanizing agent, mix, and extrude to obtain the outer rubber layer material;

[0028] S2, uniformly mixing the components except sulfur in the inner rubber layer raw material, adding sulfur to mix, and extruding to obtain the inner rubber layer material;

[0029] S3. After the inner rubber layer material is coated with rubber, an inner rubber layer is obtained, a reinforcing layer is woven on the outer surface of the inner rubber layer, the outer surface of the reinforcing layer is coated with the outer rubber layer material, and vulcanized to obtain the hydraulic hose.

[0030] As a further technical solution, in step S1, the temperature during extrusion is 80-100°C.

[0031] As a further technical solution, in step S2, the temperature during extrusion is 120-140°C.

[0032] As a further technical solution, in step S3, during the vulcanization, the temperature is 150-170° C. and the time is 10-20 min.

[0033] As a further technical solution, the thickness of the inner rubber layer is 1.5-5 mm; and / or

[0034] The thickness of the reinforcement layer is 0.5-2 mm; and / or

[0035] The thickness of the outer rubber layer is 2-6 mm.

[0036] The working principle and beneficial effects of the present invention are:

[0037] In the present invention, by optimizing the components of the outer rubber layer of the hydraulic hose, the high temperature resistance of the outer rubber layer of the hydraulic hose is significantly improved, so that after aging at 120°C for 120 hours, the absolute value of the change rate of the tensile strength is less than 5%, which broadens the application scenarios of the hydraulic hose. Among them, the nano-alumina is modified by epoxidizing natural rubber, which, on the one hand, prevents the agglomeration of the nano-alumina and improves the dispersion performance of the nano-alumina; on the other hand, the epoxy groups on the surface of the modified nano-alumina can react with the ethylene-vinyl alcohol copolymer to achieve an anchoring effect, thereby improving the high temperature resistance of the outer rubber layer. DETAILED DESCRIPTION

[0038] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the following embodiments and comparative examples, unless otherwise specified, the model of chloroprene rubber is SN232; the model of epoxidized natural rubber is ENR50; the median particle size of nano-alumina is 50 nm; the model of nitrile rubber is JSRN240S; the model of natural rubber is 20# standard rubber; the model of carbon black is N550; and the steel wire in the steel wire reinforcement layer is 321 stainless steel wire.

[0040] Example 1

[0041] A method for preparing a high temperature resistant hydraulic hose comprises the following steps:

[0042] S1, by weight, 100 parts of chloroprene rubber, 40 parts of ethylene-vinyl alcohol copolymer (model EVAL TM H171B, melt mass flow rate at 190°C and 2.16kg is 1.7g / 10min), 20 parts of modified nano-alumina, 20 parts of carbon black, 0.5 parts of m-phenylenediamine and 2 parts of antioxidant 168 are mixed evenly, and then 3 parts of vulcanizing agent DCP are added and mixed, and extruded to obtain the outer rubber layer material;

[0043] Among them, during extrusion, the temperature of zone 1 is 80°C, the temperature of zone 2 is 100°C, and the temperature of zone 3 is 90°C;

[0044] The preparation method of modified nano-alumina comprises the following steps: melting 1 part of epoxidized natural rubber at 170° C., adding 99 parts of nano-alumina, dispersing evenly, cooling, and obtaining modified nano-alumina;

[0045] S2. By weight, 100 parts of nitrile rubber, 20 parts of natural rubber, 20 parts of carbon black and 3 parts of calcium stearate were mixed evenly, 1 part of sulfur was added and mixed, and then extruded to obtain an inner rubber layer material;

[0046] Among them, during extrusion, the temperature of zone 1 is 120°C, the temperature of zone 2 is 140°C, and the temperature of zone 3 is 130°C;

[0047] S3, after the inner rubber layer material is coated with rubber, an inner rubber layer is obtained, a steel wire reinforcement layer is woven on the outer surface of the inner rubber layer, an outer rubber layer material is coated on the outer surface of the steel wire reinforcement layer, and vulcanized at 160° C. for 15 minutes to obtain a hydraulic hose;

[0048] Among them, the thickness of the inner rubber layer is 2mm, the thickness of the steel wire reinforcement layer is 0.8mm, and the thickness of the outer rubber layer is 4mm.

[0049] Example 2

[0050] A method for preparing a high temperature resistant hydraulic hose comprises the following steps:

[0051] S1, by weight, 100 parts of chloroprene rubber, 60 parts of ethylene-vinyl alcohol copolymer (model EVAL TM H171B, melt mass flow rate at 190°C and 2.16kg is 1.7g / 10min), 30 parts of modified nano-alumina, 30 parts of carbon black, 1 part of metaphenylenediamine and 4 parts of antioxidant 168 are mixed evenly, and then 5 parts of vulcanizing agent DCP are added and mixed, and extruded to obtain the outer rubber layer material;

[0052] Among them, during extrusion, the temperature of zone 1 is 80°C, the temperature of zone 2 is 100°C, and the temperature of zone 3 is 90°C;

[0053] The preparation method of modified nano-alumina comprises the following steps: melting 9 parts of epoxidized natural rubber at 170° C., adding 99 parts of nano-alumina, dispersing evenly, and cooling to obtain modified nano-alumina;

[0054] S2, by weight, 100 parts of nitrile rubber, 40 parts of natural rubber, 30 parts of carbon black and 5 parts of calcium stearate were mixed evenly, 3 parts of sulfur were added and mixed, and extruded to obtain an inner rubber layer material;

[0055] Among them, during extrusion, the temperature of zone 1 is 120°C, the temperature of zone 2 is 140°C, and the temperature of zone 3 is 130°C;

[0056] S3, after the inner rubber layer material is coated with rubber, an inner rubber layer is obtained, a steel wire reinforcement layer is woven on the outer surface of the inner rubber layer, an outer rubber layer material is coated on the outer surface of the steel wire reinforcement layer, and vulcanized at 160° C. for 15 minutes to obtain a hydraulic hose;

[0057] Among them, the thickness of the inner rubber layer is 2mm, the thickness of the steel wire reinforcement layer is 0.8mm, and the thickness of the outer rubber layer is 4mm.

[0058] Example 3

[0059] The difference between this embodiment and embodiment 2 is that in this embodiment, the model of ethylene-vinyl alcohol copolymer is EVAL TM E105B, the melt mass flow rate at 190°C and 2.16 kg is 5.7 g / 10 min.

[0060] Example 4

[0061] The difference between this embodiment and embodiment 2 is that in this embodiment, the model of ethylene-vinyl alcohol copolymer is EVAL TM C109B, the melt mass flow rate at 190°C and 2.16 kg is 9.3 g / 10 min.

[0062] Example 5

[0063] The only difference between this embodiment and embodiment 4 is that in this embodiment, the preparation method of modified nano alumina includes the following steps: melting 6 parts of epoxidized natural rubber at 170°C, adding 3 parts of 4-phenylbenzoic acid and 99 parts of nano alumina, dispersing evenly, cooling, and obtaining modified nano alumina.

[0064] Example 6

[0065] The only difference between this embodiment and embodiment 5 is that, in this embodiment, when preparing the modified nano-alumina, the weight portion of 4-phenylbenzoic acid is 1 part, and the weight portion of epoxidized natural rubber is 8 parts.

[0066] Example 7

[0067] The only difference between this embodiment and embodiment 5 is that, in this embodiment, when preparing the modified nano-alumina, the weight portion of 4-phenylbenzoic acid is 1.5 parts, and the weight portion of epoxidized natural rubber is 7.5 parts.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 1 is that step S1 of this comparative example is: by weight, 100 parts of chloroprene rubber, 40 parts of ethylene-vinyl alcohol copolymer (model EVAL TM H171B, melt mass flow rate at 190°C and 2.16kg is 1.7g / 10min), 0.2 parts of epoxidized natural rubber, 19.8 parts of nano-alumina, 20 parts of carbon black, 0.5 parts of m-phenylenediamine and 2 parts of antioxidant 168 are mixed evenly, and then 3 parts of vulcanizing agent DCP are added and mixed, and extruded to obtain the outer rubber layer material;

[0070] During extrusion, the temperature of zone 1 is 80°C, the temperature of zone 2 is 100°C, and the temperature of zone 3 is 90°C.

[0071] Comparative Example 2

[0072] The only difference between this comparative example and Example 1 is that in this comparative example, the preparation method of modified nano alumina includes the following steps: melting 1 part of natural rubber at 170° C., adding 99 parts of nano alumina, dispersing evenly, and cooling to obtain modified nano alumina.

[0073] Comparative Example 3

[0074] The only difference between this comparative example and Example 1 is that in this comparative example, the modified nano-alumina is replaced by an equal amount of nano-alumina.

[0075] The outer rubber layer of the hydraulic hose in Examples 1 to 7 and Comparative Examples 1 to 3 was peeled off, and the tensile strength was measured with reference to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", wherein the specimen was a 1A dumbbell-shaped specimen, and the average value of the results of the three specimens was taken as the final result; the test was carried out with reference to GB / T 3512-2014 "Hot air accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber", and the tensile strength of each specimen after the test was tested according to the above-mentioned tensile strength test method, and the change rate of the tensile strength was calculated, and the result was retained to two decimal places, wherein, during the test, the cabinet-type hot air aging box in method A was used, the air was changed 5 times per hour, the temperature was 120°C, and the time was 120h.

[0076] The test results are shown in Table 1 below.

[0077] Table 1 Hydraulic hose outer layer performance test results

[0078]

[0079] The comparison between Example 1 and Comparative Examples 1 to 3 shows that the high temperature resistance of the outer rubber layer can be significantly improved by modifying the nano-alumina by epoxidizing natural rubber. The comparison between Example 2 and Examples 3 to 4 shows that when the melt mass flow rate of ethylene-vinyl alcohol copolymer at 190°C and 2.16kg is ≥5.7g / 10min, it helps to further improve the high temperature resistance of the outer rubber layer of the hydraulic hose. The comparison between Example 4 and Examples 5 to 7 shows that when the modifier also includes 4-phenylbenzoic acid, the high temperature resistance of the outer rubber layer of the hydraulic hose can be further improved. The comparison between Example 5 and Examples 6 to 7 shows that when the weight ratio of 4-phenylbenzoic acid to epoxidized natural rubber is 1:5 to 8, it helps to further improve the high temperature resistance of the outer rubber layer of the hydraulic hose.

[0080] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high temperature resistant hydraulic hose, characterized in that: The invention comprises an inner rubber layer, a reinforcing layer and an outer rubber layer which are sequentially arranged from the inside to the outside, wherein the raw materials of the outer rubber layer comprise the following components in parts by weight: 100 parts of chloroprene rubber, 40-60 parts of ethylene-vinyl alcohol copolymer, 20-30 parts of modified nano-alumina, 20-30 parts of carbon black, 0.5-1 parts of m-phenylenediamine, 3-5 parts of vulcanizing agent and 2-4 parts of antioxidant; The raw materials of the modified nano-alumina include a modifier and nano-alumina in a weight ratio of 1 to 9:99; The modifier includes epoxidized natural rubber; The melt mass flow rate of the ethylene-vinyl alcohol copolymer at 190° C. and 2.16 kg is ≥5.7 g / 10 min; The modifier also includes 4-phenylbenzoic acid, and the weight ratio of the 4-phenylbenzoic acid to the epoxidized natural rubber is 1:5-8.

2. A high temperature resistant hydraulic hose according to claim 1, characterized in that: The raw materials of the inner rubber layer include the following components in parts by weight: 100 parts of nitrile rubber, 20-40 parts of natural rubber, 20-30 parts of carbon black, 3-5 parts of calcium stearate, and 1-3 parts of sulfur.

3. A high temperature resistant hydraulic hose according to claim 1, characterized in that: The reinforcement layer is a steel wire reinforcement layer.

4. A high temperature resistant hydraulic hose according to claim 1, characterized in that: The vulcanizing agent includes one or more of the vulcanizing agent DCP, the vulcanizing agent DBPH, and the vulcanizing agent DTBP.

5. A high temperature resistant hydraulic hose according to claim 1, characterized in that: The antioxidant includes one or more of antioxidant 264 , antioxidant 168 , and antioxidant 2246 .

6. The method for preparing a high temperature resistant hydraulic hose according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Evenly mix the components except the vulcanizing agent in the outer rubber layer raw material, add the vulcanizing agent, mix, and extrude to obtain the outer rubber layer material; S2, uniformly mixing the components except sulfur in the inner rubber layer raw material, adding sulfur to mix, and extruding to obtain the inner rubber layer material; S3. After the inner rubber layer material is coated with rubber, an inner rubber layer is obtained, a reinforcing layer is woven on the outer surface of the inner rubber layer, the outer surface of the reinforcing layer is coated with the outer rubber layer material, and vulcanized to obtain the hydraulic hose.

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