Modified tire steel wire rubber composition and preparation method thereof

Abstract

The invention relates to the technical field of rubber composite materials, in particular to a modified tire steel wire rubber composition and a preparation method thereof. The composition is prepared from the following raw materials: diene rubber, a reinforcing material, a polymaleimide composition, sulfur, an accelerant, zinc oxide and an anti-aging agent. The tire steel wire rubber composition based on multi-maleimide modification provided by the invention has the excellent properties of high modulus, strong bonding performance, excellent heat and aging resistance and small hysteresis loss.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber composites, and in particular to a modified tire steel cord rubber composition and a preparation method thereof. BACKGROUND

[0002] Tire steel cord rubber is a key material in tire manufacturing, and its performance directly affects the durability, safety and rolling resistance of the tire. Traditional steel cord rubber formulations often use natural rubber (NR) or synthetic rubber (such as SBR, BR) as the matrix, combined with a sulfur vulcanization system, carbon black reinforcing agent and an adhesion system (cobalt salt, m-cresol formaldehyde resin and hexamethoxymethyl melamine (HMMM)).

[0003] For example, Japanese patent application JP2002038113A provides a rubber composition for adhering steel cord, and the composition prepared using the m-cresol-white adhesion system has excellent initial adhesion, while improving the rubber breaking resistance. However, the tire steel cord rubber prepared using the above system still has the following problems: 1) under high temperature or hot and humid environment, the rubber and steel wire interface is easily oxidized and degraded, resulting in a decrease in adhesion after aging. 2) The modulus of the traditional formula decays significantly under dynamic load, and the lack of modulus affects the supportability of the tire. 3) The loss factor (tan δ) is high, which increases the rolling resistance of the tire and reduces fuel efficiency. SUMMARY

[0004] To solve the above technical problems, the present application provides a modified tire steel cord rubber composition, and the preparation raw materials of the composition include: diene rubber, reinforcing material, multi-maleimide composition, sulfur, accelerator, zinc oxide and antioxidant.

[0005] In one embodiment, the preparation raw materials of the composition include: diene rubber 60-140 parts, reinforcing material 10-100 parts, multi-maleimide composition 0.5-5 parts, sulfur 1-10 parts, accelerator 0.5-2 parts, zinc oxide 3-12 parts and antioxidant 1-5 parts, by weight.

[0006] In one embodiment, the preparation raw materials of the composition include: diene rubber 100-120 parts, reinforcing material 10-60 parts, multi-maleimide composition 1-3 parts, sulfur 5-8 parts, accelerator 1-2 parts, zinc oxide 8-10 parts and antioxidant 2-4 parts, by weight.

[0007] In one embodiment, the structural general formula of the multi-maleimide composition includes at least one of formula 1 and formula 2:

[0008] Formula 1: Formula 2: In Formula 1, A is selected from one of aryl, aralkyl, aryl ether bond group having 6-24 carbon atoms; x and y are both integers from 0-5; in Formula 2, n is an integer from 0-20.

[0009] In an embodiment, the multi-maleimide composition includes one or more of N,N'-m-phenylene bismaleimide, diphenylmethane maleimide, bismaleimide, polymeric multi-maleimide.

[0010] In an embodiment, the diene rubber includes one or more of natural rubber, synthetic polyisoprene rubber, styrene butadiene rubber, cis-butadiene rubber.

[0011] In an embodiment, the reinforcing material includes at least one of carbon-based reinforcing material, diatomite reinforcing material.

[0012] In an embodiment, the carbon-based reinforcing material is carbon black, and the type of the carbon black includes one or more of N110, N121, N134, N220, N231, N234, N242, N326, N330, N332, N339, N343, N347, N375, N550.

[0013] In an embodiment, the diatomite reinforcing material is silicon dioxide, and the CTAB adsorption specific surface area of the silicon dioxide is 100-300 m 2 / g.

[0014] In an embodiment, the accelerator is a sulfenamide type accelerator.

[0015] In an embodiment, the sulfenamide type accelerator is one or more of accelerator CZ, accelerator DZ, accelerator NS.

[0016] In an embodiment, the preparation raw material further includes 0.1-5 parts of cobalt salt by weight, and the cobalt salt includes one or more of cobalt naphthenate, cobalt stearate, cobalt neodecanoate, and boron acylated cobalt.

[0017] In an embodiment, the antioxidant is a p-phenylenediamine type antioxidant or a quinoline type antioxidant.

[0018] In an embodiment, the p-phenylenediamine type antioxidant includes N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD).

[0019] In an embodiment, the quinoline type antioxidant includes 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMQ).

[0020] In an embodiment, the sulfur is insoluble sulfur; further optionally, oil-extended insoluble sulfur.

[0021] In an embodiment, the zinc oxide is one or more of indirect zinc oxide, precipitated zinc oxide.

[0022] The present application adopts a multi-maleimide composition as an important component in the adhesive system. On the one hand, it undergoes an "ene-mercapto" click reaction with the double bonds of the rubber chain during vulcanization, forming a three-dimensional crosslinked network, increasing the crosslinking density and modulus. On the other hand, the maleimide group is combined with the oxide layer (FeO / Fe3O4) on the surface of the steel wire through coordination bond, enhancing the interfacial adhesion. At the same time, the crosslinked structure of multi-maleimide inhibits the diffusion of oxygen, and cooperates with antioxidant 6PPD / TMQ to delay the degradation of rubber. The cobalt salt in the system acts as a catalyst activator, which can promote the reaction between sulfur in rubber and zinc on the surface of steel wire, inhibit oxidation and optimize the interface results, and improve the adhesion strength and corrosion resistance of rubber and steel wire. In the present application, the amount of cobalt salt is controlled to avoid the phenomenon that the hysteresis loss of rubber increases due to cobalt ions under dynamic deformation.

[0023] The second aspect of the present application provides a preparation method of a modified tire steel wire rubber composition, at least comprising:

[0024] S1, mixing diene rubber, and then putting the remaining preparation raw materials except sulfur and accelerator into secondary mixing to obtain a rubber compound;

[0025] S2, plasticizing sulfur and accelerator into the rubber compound to obtain the modified tire steel wire rubber composition.

[0026] In an embodiment, the S1 step comprises: mixing diene rubber for 60-80s, mixing reinforcing materials and zinc oxide for 120-200s, and then adding the remaining preparation raw materials except sulfur and accelerator to mix until 150-160℃ to obtain a rubber compound.

[0027] In an embodiment, the plasticizing time is 60-120s, and the temperature is 60-100℃.

[0028] Beneficial effects:

[0029] The present application provides a modified tire steel wire rubber composition and a preparation method, which has the following advantages:

[0030] (1) The traditional tire steel cord adhesive system relies on the "meta-cresol-white" system (methylene acceptor such as resorcinol, meta-cresol formaldehyde resin + methylene donor such as HMMM / HMT + white carbon black), and the present application completely abandons such components, uses a multi-maleimide composition as an important component in the adhesive system, increases the crosslinking density and modulus, enhances the interfacial adhesion, and the crosslinking structure of the multi-maleimide inhibits the diffusion of oxygen, and cooperates with the antioxidant 6PPD / TMQ to delay the degradation of the rubber.

[0031] (2) The tire steel cord adhesive composition provided by the present application has high modulus, strong adhesion, excellent heat resistance and aging resistance, and excellent performance of small hysteresis loss.

[0032] (3) The tire steel cord adhesive composition prepared by the present application still has excellent adhesion strength in a high-temperature and humid heat environment, and the adhesion performance test shows that the steel cord pull-out force is ≥800 N / cm after 100°C*72h heat aging and 70°C*80%RH*168h humid heat aging.

[0033] (4) The modulus of the tire steel cord adhesive composition prepared by the present application is obviously improved compared with that of the tire steel cord adhesive prepared by the traditional formula, the 100% modulus is increased by 8-13%, and the 300% modulus is increased by 5-10%.

[0034] (5) The tan δ value of the tire steel cord adhesive composition prepared by the present application at 60°C is reduced by 6%-15% compared with that of the tire steel cord adhesive prepared by the traditional formula, and the rolling resistance is significantly reduced. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below with reference to the examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. The experimental methods not specified in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not specified by the manufacturer are all conventional products that can be purchased on the market.

[0036] Example 1

[0037] The first aspect of this example provides a modified tire steel cord adhesive composition, and the preparation raw materials of the composition include, in terms of parts by weight: diene rubber 100 parts, reinforcing material 52 parts, multi-maleimide composition 1 part, sulfur 8 parts, accelerator 1 part, zinc oxide 10 parts, cobalt salt 1.2 parts, and antioxidant 2 parts.

[0038] The diene rubber is natural rubber, 3# smoke sheet rubber from Vietnam.

[0039] The reinforcing material is carbon black, model N110.

[0040] The multi-maleimide composition is polymeric multi-maleimide, model RBMI2300-B, from Shandong Rui Ba New Material Technology Co., Ltd.

[0041] The sulfur is insoluble sulfur.

[0042] The accelerator is accelerator CZ.

[0043] The cobalt salt is cobalt neodecanoate.

[0044] The zinc oxide is indirect method zinc oxide.

[0045] The antioxidant is N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine.

[0046] The second aspect of the example provides a preparation method of a modified tire steel cord rubber composition, comprising:

[0047] S1, mixing diene rubber for 60s at a speed of 50r / min, mixing reinforcing material and zinc oxide for 160s, then adding cobalt salt, antioxidant and multi-maleimide composition to mix to 160°C, and unloading the rubber to a mill for thin pass cooling to below 60°C;

[0048] S2, mixing sulfur and accelerator into the mixed rubber for 100s at a temperature of 80°C, and then mixing for 6 times of triangle bag; subsequently, adjusting the roll gap to 3mm, and finishing the rubber to obtain the modified tire steel cord rubber composition.

[0049] Example 2

[0050] The specific implementation of the example is the same as that of example 1, except that the preparation raw materials of the composition include, by weight fraction, diene rubber 100 parts, reinforcing material 52 parts, multi-maleimide composition 2 parts, sulfur 8 parts, accelerator 1 part, zinc oxide 10 parts, cobalt salt 1.2 parts and antioxidant 2 parts.

[0051] Example 3

[0052] The specific implementation of the example is the same as that of example 1, except that the preparation raw materials of the composition include, by weight fraction, diene rubber 100 parts, reinforcing material 52 parts, multi-maleimide composition 3 parts, sulfur 8 parts, accelerator 1 part, zinc oxide 10 parts and antioxidant 2 parts.

[0053] Example 4

[0054] The specific embodiment of this example is the same as that of Example 1, except that the raw materials for preparing the composition include, by weight fraction, 100 parts of diene rubber, 52 parts of reinforcing material, 1 part of the multi-maleimide composition, 8 parts of sulfur, 1 part of accelerator, 10 parts of zinc oxide, 1.2 parts of cobalt salt, and 2 parts of antioxidant.

[0055] The multi-maleimide composition is N,N'-m-phenylene bismaleimide (PDM) from Shandong Ruiba New Material Technology Co., Ltd.

[0056] Example 5

[0057] The specific embodiment of this example is the same as that of Example 1, except that the raw materials for preparing the composition include, by weight fraction, 100 parts of diene rubber, 52 parts of reinforcing material, 1 part of the multi-maleimide composition, 8 parts of sulfur, 1 part of accelerator, 10 parts of zinc oxide, 1.2 parts of cobalt salt, and 2 parts of antioxidant.

[0058] The multi-maleimide composition is diphenylmethane bismaleimide (BMI1000) from Shandong Ruiba New Material Technology Co., Ltd.

[0059] Example 6

[0060] The specific embodiment of this example is the same as that of Example 1, except that the raw materials for preparing the composition include, by weight fraction, 100 parts of diene rubber, 55 parts of reinforcing material, 2 parts of the multi-maleimide composition, 5 parts of sulfur, 1.2 parts of accelerator, 8 parts of zinc oxide, 0.5 parts of cobalt salt, and 2 parts of antioxidant.

[0061] The accelerator is accelerator NS.

[0062] Example 7

[0063] The specific embodiment of this example is the same as that of Example 1, except that the raw materials for preparing the composition include, by weight fraction, 100 parts of diene rubber, 55 parts of reinforcing material, 2.5 parts of the multi-maleimide composition, 5 parts of sulfur, 1.2 parts of accelerator, 8 parts of zinc oxide, and 2 parts of antioxidant.

[0064] The accelerator is accelerator NS.

[0065] Example 8

[0066] The specific embodiment of this example is the same as that of Example 1, except that the raw materials for preparing the composition include, by weight fraction, 100 parts of diene rubber, 55 parts of reinforcing material, 2.5 parts of the multi-maleimide composition, 5 parts of sulfur, 1.2 parts of accelerator, 8 parts of zinc oxide, and 2 parts of antioxidant.

[0067] The accelerator is accelerator NS.

[0068] The multi-maleimide composition is N,N'-m-phenylene bismaleimide (PDM), diphenylmethane maleimide (BMI 1000), and polymeric multi-maleimide (RBMI 2300-B) mixed in a mass ratio of 1:1:1.

[0069] Comparative Example 1

[0070] The specific embodiment of this example is the same as that of Example 1, except that the raw materials for preparing the composition include, by weight fraction, 100 parts of diene rubber, 52 parts of reinforcing material, 8 parts of sulfur, 1 part of accelerator, 10 parts of zinc oxide, 1.2 parts of cobalt salt, and 2 parts of antioxidant.

[0071] Comparative Example 2

[0072] The specific embodiment of this example is the same as that of Example 1, except that the raw materials for preparing the composition include, by weight fraction, 100 parts of diene rubber, 55 parts of reinforcing material, 5 parts of sulfur, 1 part of accelerator, 8 parts of zinc oxide, 0.2 parts of cobalt salt, 2 parts of antioxidant, 1.5 parts of m-cresol formaldehyde resin RN-3260, and 3 parts of hexamethoxymethyl melamine HMMM-60%.

[0073] Performance Test

[0074] The samples prepared in Examples 1-8 and Comparative Examples 1-2 were vulcanized on a flat plate vulcanization machine, and the tensile test samples were vulcanized at 150°C for 35 min, and the wire pull-out test samples were vulcanized at 150°C for 45 min. The test contents and data are shown in Tables 1 and 2.

[0075] Test Method and Standard:

[0076] 1) Hardness: According to GB / T531 Vulcanized Rubber or Thermoplastic Rubber Indentation Hardness Test Method, the test temperature was room temperature.

[0077] 2) Mechanical Properties: According to GB / T528-2009 Vulcanized Rubber or Thermoplastic Rubber Tensile Stress-Strain Properties Test, the test temperature was room temperature.

[0078] 3) Tear Strength: According to GB / T529-2008 Vulcanized Rubber or Thermoplastic Rubber Tear Strength Test, the test temperature was room temperature.

[0079] 4) Aging Coefficient: The rubber was aged in a 100°C * 48 hour aging oven, and the higher the aging coefficient, the better the heat and oxygen aging resistance.

[0080] 5) Dynamic performance: tested by DMA850 equipment, test conditions: dynamic tensile properties under the condition of frequency 10HZ, deformation 0.25%, temperature range -80℃~+70℃, heating rate 1.5℃ / min.

[0081] 6) Crosslinking density: according to GB / T16584-1996, the higher the MH-ML value, the higher the crosslinking network density.

[0082] 7) Adhesion test: according to GB / T16586-2014, the test sample is tested after heat aging, humidity aging and salt spray aging respectively.

[0083] Table 1

[0084]

[0085]

[0086] Table 2

[0087]

[0088] From the test data in Table 1 and Table 2, it can be seen that the tire steel cord rubber composition prepared by using the multi-maleimide composition as the adhesive system has high modulus, strong adhesion, excellent heat resistance and aging resistance, and small hysteresis loss.

Claims

1. A modified tire steel wire rubber composition, characterized in that, The raw materials for preparing the composition include: diene rubber, reinforcing material, domaleimide composition, sulfur, accelerator, zinc oxide and antioxidant.

2. The modified tire steel wire rubber composition according to claim 1, characterized in that, The raw materials for preparing the composition, by weight, include: 60-140 parts of diene rubber, 10-100 parts of reinforcing material, 0.5-5 parts of domaleimide composition, 1-10 parts of sulfur, 0.5-2 parts of accelerator, 3-12 parts of zinc oxide, and 1-5 parts of antioxidant.

3. The modified tire steel wire rubber composition according to claim 2, characterized in that, The general structural formula of the polymaleimide composition includes at least one of Formula 1 and Formula 2: Formula 1: Formula 2: In Formula 1, A is selected from one of the aryl, aralkyl, or aryl ether groups with 6-24 carbon atoms; x and y are both integers from 0 to 5; in Formula 2, n is an integer from 0 to 20.

4. The modified tire steel wire rubber composition according to claim 3, characterized in that, The polymaleimide composition includes one or more of N,N'-m-phenylenebismaleimide, diphenylmethanemaleimide, bismaleimide, and polymeric polymaleimide.

5. The modified tire steel wire rubber composition according to claim 2, characterized in that, The diene-based rubbers include one or more of natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber, and cis-butadiene rubber.

6. The modified tire steel wire rubber composition according to claim 2, characterized in that, The reinforcing material includes at least one of carbon-based reinforcing materials and diatomaceous earth reinforcing materials.

7. The modified tire steel wire rubber composition according to claim 2, characterized in that, The accelerator is a sulfenamide accelerator.

8. The modified tire steel wire rubber composition according to claim 2, characterized in that, The raw materials for preparation also contain 0.1-5 parts by weight of cobalt salt, which includes one or more of cobalt naphthenate, cobalt stearate, cobalt neodecanoate, and cobalt borate.

9. The modified tire steel wire rubber composition according to claim 2, characterized in that, The antioxidant is a p-phenylenediamine antioxidant or a quinoline antioxidant.

10. A method for preparing a modified tire steel wire rubber composition according to any one of claims 1-9, characterized in that, At least including: S1. The diene rubber is mixed and then mixed again with the remaining raw materials (excluding sulfur and accelerator) to obtain the rubber compound. S2. Sulfur and accelerator are added to the rubber compound and plasticized to obtain the modified tire steel wire rubber composition.

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