Aging-resistant rubber and tire

Abstract

This invention belongs to the field of polymer material processing and modification, and particularly relates to an aging-resistant rubber and a tire. Specifically, this invention relates to a composition for preparing rubber, a rubber obtained by refining said composition, and a tire containing said rubber. This invention also relates to a method for preparing said rubber.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polymer material processing modification, and particularly relates to a composition for preparing rubber, rubber obtained by mixing the composition, and a tire comprising the rubber. The present application also relates to a method for preparing the rubber. BACKGROUND

[0002] Tires are always subjected to cyclic compression deformation and abrasion during automobile driving, in the process, ozone and ultraviolet light react with the tire to continuously damage it, and the tire is also subjected to external mechanical force, so the tire material is usually required to have excellent resistance to aging cracking and abrasion. In the existing rubber tire preparation technology, natural rubber with excellent comprehensive performance is usually selected as the main material. However, due to the carbon-carbon double bond in the main chain and the methyl group in the side chain of natural rubber, the rubber surface is easily affected by the external environment to produce aging cracks, and as the cracks continuously expand to the inside, the strength and service life of the rubber track are reduced.

[0003] To prevent aging cracking, the existing technology mainly uses a surface coating of paraffin wax or phenolic resin as an anti-ozone aging protective layer.

[0004] The method of surface coating of anti-ozone aging agent is only suitable for static rubber products and cannot be used for rubber tires.

[0005] Therefore, it is necessary to develop an aging-resistant rubber material with excellent performance and suitable for dynamic rubber products. SUMMARY

[0006] One of the purposes of the present application is to provide a rubber that can improve the aging resistance of the tire while maintaining high strength and improving the service life.

[0007] The aging-resistant rubber provided by the present application comprises raw rubber, compounding agents and other components. It is prepared by adding melamine cyanurate complex (MCA), polyolefin elastomer, styrene block copolymer (SEBS), microcrystalline wax, antioxidant and other additives. Compared with the prior art, the present application uses natural rubber and ethylene-propylene-diene rubber mixed rubber to add melamine cyanurate complex (MCA), polyolefin elastomer and styrene block copolymer (SEBS) to form a protective network resistant to ozone and ultraviolet aging, which protects the main natural rubber from ozone and ultraviolet light erosion while maintaining high strength of the rubber, effectively avoids the generation of surface cracking of the rubber, improves the aging resistance of the tire, and prolongs the service life.

[0008] In one aspect, the present application provides a composition for preparing rubber, comprising by weight ratio: raw rubber 100 parts, melamine cyanurate complex (MCA) 4-7 parts (for example 4, 5, 6 or 7 parts), polyolefin elastomer 5-10 parts (for example 5, 6, 7, 8, 9 or 10 parts), styrene block copolymer (SEBS) 5-10 parts (for example 5, 6, 7, 8, 9 or 10 parts), carbon black 35-60 parts (for example 35, 40, 45, 50, 55 or 60 parts), zinc oxide 3-6 parts (for example 3, 4, 5 or 6 parts), stearic acid 2-4 parts (for example 2, 3 or 4 parts), sulfur 3-5 parts (for example 3, 4 or 5 parts), accelerator 1.5-2 parts (for example 1.5, 1.6, 1.7, 1.8, 1.9 or 2 parts), antioxidant 1-3 parts (for example 1, 2 or 3 parts), aromatic oil 15-20 parts (for example 15, 16, 17, 18, 19 or 20 parts), microcrystalline wax HG75 2-4 parts (for example 2, 3 or 4 parts);

[0009] wherein the raw rubber is a mixture of natural rubber and ethylene-propylene-diene rubber in a weight ratio of 7:2-9:2 (for example 8:2);

[0010] The carbon black is one or more of N220, N234 and N326;

[0011] The accelerator is one or more of AZ, BZ and TMTD;

[0012] The antioxidant is a mixture of MB and DFC-34 in a weight ratio of 2:1-4:1 (for example 3:1).

[0013] Herein, SEBS is a linear tri-block copolymer with polystyrene as end segment and ethylene-butene copolymer obtained by hydrogenation of polybutadiene as middle elastic segment, free of unsaturated double bonds, having good stability and aging resistance, and good aging resistance to light oxygen and ozone, and its product is suitable for outdoor use.

[0014] The polyolefin elastomer is a high-performance polyolefin, which has excellent aging resistance to heat aging and ultraviolet light.

[0015] Melamine cyanurate complex (MCA) is a complex generated by reaction of melamine and cyanuric acid, which has significant flame retardant effect and good lubricating property, and can be used as resin flame retardant, solid lubricant, additive of lubricating oil and grease, etc.

[0016] MCA, polyolefin elastomer and SEBS are all commercially available products.

[0017] N220, N234, N326 are carbon black grades. AZ, BZ, TMTD are accelerator grades. MB, DFC-34 are antioxidant grades. The above agents are all commercially available products, and the information of the accelerators and antioxidants is as follows:

[0018]

[0019] In certain embodiments, the composition for preparing rubber comprises: raw rubber, melamine cyanurate complex (MCA), polyolefin elastomer, styrene block copolymer (SEBS), carbon black N234, zinc oxide, stearic acid, sulfur, accelerator BZ, antioxidant, aromatic oil, microcrystalline wax HG75.

[0020] In certain embodiments, the composition for preparing rubber comprises: raw rubber 100 parts, melamine cyanurate complex (MCA) 4-7 parts, polyolefin elastomer 5-10 parts, styrene block copolymer (SEBS) 5-10 parts, carbon black N234 50 parts, zinc oxide 4 parts, stearic acid 3 parts, sulfur 4 parts, accelerator BZ 2 parts, antioxidant 2 parts, aromatic oil 20 parts, microcrystalline wax HG75 2 parts.

[0021] In one aspect, the present application provides a rubber obtained by milling the composition of any one of the above.

[0022] The rubber of the present application has high strength, good toughness, and excellent aging resistance. In certain embodiments, the rubber has one or more of the following characteristics:

[0023] Tensile strength: 25.2-26.7 MPa;

[0024] Elongation at break: 398%-412%;

[0025] Ozone aging resistance test (elongation 20%, ozone concentration 50 ppm, temperature 50℃, humidity 55%): no cracking for 240h.

[0026] Ultraviolet light aging (irradiance 0.49W / m 2 , temperature 70℃, 8h; condensation 50℃, 4h, test 45 cycles): tensile strength retention rate 95%-96%, elongation at break retention rate 91%-94%.

[0027] The determination method of the above performance parameters can refer to the methods commonly used in the art, such as the methods specified in GB / T 528-2009, GB / T 7762-2014, GB / T 16585-1996, etc.

[0028] In addition, the present application also provides the use of the rubber of any one of the above for preparing tires.

[0029] The application also provides a tire comprising the rubber of any one of the above, or made from the composition or rubber of any one of the above.

[0030] Further, the application provides a vehicle or engineering machinery comprising the tire of the above.

[0031] The application also provides a method for preparing the rubber of the application, comprising the step of mixing using the composition of any one of the above.

[0032] In some embodiments, the method comprises: ingredient preparation, plasticizing, mixing, final mixing.

[0033] In some embodiments, the method comprises the following steps:

[0034] (1) Ingredient preparation: prepare a mixture of natural rubber and ethylene-propylene-diene rubber, cut into wedge-shaped pieces, and then dry; dry and sieve the other ingredients in the composition, and weigh them according to the proportion;

[0035] (2) Plasticizing: set the speed ratio of the front and rear rollers of the open mill to 1:1.5-1:2, adjust the roller distance of the open mill to 0.5-0.6 mm, add the mixture of natural rubber and ethylene-propylene-diene rubber for plasticizing, and pack 3 times;

[0036] (3) Mixing: adjust the roller distance to 0.8-0.9 mm, and add the mixture of natural rubber and ethylene-propylene-diene rubber for mixing.

[0037] (4) Final mixing: add the mixed rubber in the open mill, and then add the other ingredients for final mixing. After the powder is finished, pack 8-10 times to make the ingredients evenly dispersed; then, the rubber is sheeted, and is parked for 5-8 hours.

[0038] Advantages of the application

[0039] The rubber provided by the application has one or more of the following advantages:

[0040] (1) The rubber prepared using the formulation components provided by the application has excellent tensile properties and aging resistance, greatly improving the anti-cracking performance of rubber tires;

[0041] (2) The rubber obtained by the application has excellent aging resistance, and is not only suitable for rubber products that are placed statically, but also suitable for rubber tires that move at high speed. DETAILED DESCRIPTION

[0042] The embodiments of the present application will be described in detail below with examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions not noted in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not noted by the manufacturer, which are all conventional products that can be obtained by purchase.

[0043] Example 1

[0044] The present example provides a kind of anti-aging rubber, which is prepared from the following raw materials by weight parts, including raw rubber 100 parts, melamine cyanurate complex (MCA) 4 parts, polyolefin elastomer 5 parts, styrene block copolymer (SEBS) 5 parts, carbon black N234 50 parts, zinc oxide 4 parts, stearic acid 3 parts, sulfur 4 parts, accelerator BZ 2 parts, antioxidant (MB, DFC-34, weight ratio 3:1) 2 parts, aromatic oil 20 parts, microcrystalline wax HG75 2 parts.

[0045] (1) Preparation of ingredients: prepare the mixture of natural rubber and ethylene-propylene-diene rubber (weight ratio 8:2), cut into wedge-shaped block, and then dry; other ingredients in the composition are respectively crushed and dried, and then sieved, weighed according to the proportion for use;

[0046] (2) Plasticizing: the speed ratio of the front and rear rollers of the open mill is set to 1:1.5, the roller distance of the open mill is adjusted to 0.6 mm, the mixture of natural rubber and ethylene-propylene-diene rubber is added for plasticizing, and packed 3 times;

[0047] (3) Mixing: adjust the roller distance to 0.8 mm, and add the mixture of natural rubber and ethylene-propylene-diene rubber for mixing.

[0048] (4) Final mixing: add the mixed rubber in the open mill, then add other ingredients for final mixing, and after completing the powdering, pack 10 times to make the ingredients evenly dispersed; then the rubber is sheeted, and stored for 6 hours.

[0049] Example 2

[0050] The present example provides a kind of anti-aging rubber, which is prepared from the following raw materials by weight parts, including raw rubber 100 parts, melamine cyanurate complex (MCA) 5 parts, polyolefin elastomer 8 parts, styrene block copolymer (SEBS) 8 parts, carbon black N234 50 parts, zinc oxide 4 parts, stearic acid 3 parts, sulfur 4 parts, accelerator BZ 2 parts, antioxidant (MB, DFC-34, weight ratio 3:1) 2 parts, aromatic oil 20 parts, microcrystalline wax HG75 2 parts.

[0051] (1) Preparation of ingredients: prepare a mixture of natural rubber and ethylene-propylene-diene rubber (weight ratio 8:2), cut into wedge-shaped blocks, and then dry; other ingredients in the composition are separately crushed and dried, sieved, weighed according to the proportion, and used;

[0052] (2) Plastication: set the speed ratio of the front and rear rollers of the open mill to 1:1.5, adjust the roller gap of the open mill to 0.6 mm, add the mixture of natural rubber and ethylene-propylene-diene rubber for plastication, and pack 3 times;

[0053] (3) Mixing: adjust the roller gap to 0.8 mm, and add the mixture of natural rubber and ethylene-propylene-diene rubber for mixing.

[0054] (4) Final mixing: add the mixed rubber into the open mill, then add other ingredients for final mixing, and after completing the powdering, pack 10 times to make the ingredients evenly dispersed; then the rubber is sheeted and stored for 6 hours.

[0055] Example 3

[0056] The present example provides a kind of anti-aging rubber, which is prepared from the following raw materials by weight parts, wherein it contains raw rubber 100 parts, melamine cyanurate complex (MCA) 7 parts, polyolefin elastomer 10 parts, styrene block copolymer (SEBS) 10 parts, carbon black N234 50 parts, zinc oxide 4 parts, stearic acid 3 parts, sulfur 4 parts, accelerator BZ 2 parts, antioxidant (MB, DFC-34, weight ratio 3:1) 2 parts, aromatic oil 20 parts, microcrystalline wax HG75 2 parts.

[0057] (1) Preparation of ingredients: prepare a mixture of natural rubber and ethylene-propylene-diene rubber (weight ratio 8:2), cut into wedge-shaped blocks, and then dry; other ingredients in the composition are separately crushed and dried, sieved, weighed according to the proportion, and used;

[0058] (2) Plastication: set the speed ratio of the front and rear rollers of the open mill to 1:1.5, adjust the roller gap of the open mill to 0.6 mm, add the mixture of natural rubber and ethylene-propylene-diene rubber for plastication, and pack 3 times;

[0059] (3) Mixing: adjust the roller gap to 0.8 mm, and add the mixture of natural rubber and ethylene-propylene-diene rubber for mixing.

[0060] (4) Final mixing: add the mixed rubber into the open mill, then add other ingredients for final mixing, and after completing the powdering, pack 10 times to make the ingredients evenly dispersed; then the rubber is sheeted and stored for 6 hours.

[0061] Comparative Example 1

[0062] This comparative example uses the following raw materials in parts by weight: 100 parts raw rubber, 50 parts carbon black N234, 4 parts zinc oxide, 3 parts stearic acid, 4 parts sulfur, 2 parts accelerator BZ, 2 parts antioxidant DFC-34, 20 parts aromatic oil, and 2 parts microcrystalline wax HG75.

[0063] (1) Ingredient preparation: Prepare a mixture of natural rubber and EPDM rubber (weight ratio of 8:2), cut it into wedge-shaped pieces, and then dry it; crush and dry the other components in the composition separately, sieve them, and weigh them according to the proportion for later use;

[0064] (2) Plasticizing: Set the speed ratio of the front and rear rollers of the open mill to 1:1.5, adjust the roller gap of the open mill to 0.6mm, add the mixture of natural rubber and EPDM rubber for plasticizing, and pack it 3 times.

[0065] (3) Mixing: Adjust the roller gap to 0.8mm and add the mixture of natural rubber and EPDM rubber to the mixing.

[0066] (4) Final mixing: Add the compounded rubber to the open mill, then add other components for final mixing. After the powder is absorbed, pack it 10 times to ensure that the components are evenly dispersed. Then the rubber compound is sheeted and left to stand for 6 hours.

[0067] The performance test results of the rubbers prepared in several embodiments and comparative examples are shown in Table 1.

[0068] Table 1. Rubber performance test results

[0069]

[0070] The results above show that the rubber obtained in Examples 1-3 has sufficient strength and toughness to meet the requirements for use, and its aging resistance is better than that of Comparative Example 1.

[0071] The aging-resistant rubber and tires prepared by the above method according to the present invention can meet actual needs by adjusting the raw rubber and compounding agents. In the various embodiments of the present invention, the sequence numbers or order of the embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of each embodiment have different focuses; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0072] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A composition for preparing rubber, comprising, by weight: 100 parts raw rubber, 4-7 parts melamine cyanuric acid complex, 5-10 parts polyolefin elastomer, 5-10 parts styrene block copolymer SEBS, 35-60 parts carbon black, 3-6 parts zinc oxide, 2-4 parts stearic acid, 3-5 parts sulfur, 1.5-2 parts accelerator, 1-3 parts antioxidant, 15-20 parts aromatic oil, and 2-4 parts microcrystalline wax HG75; in, The raw rubber is a mixture of natural rubber and EPDM rubber in a weight ratio of 7:2 to 9:2; The carbon black is one or a mixture of N220, N234, and N326; The accelerator is one or more of AZ, BZ, and TMTD; The antioxidant is a mixture of MB and DFC-34 in a weight ratio of 2:1 to 4:

1.

2. A rubber obtained by refining the composition of claim 1.

3. The rubber of claim 2, having one or more of the following characteristics: (1) Tensile strength: 25.2~26.7 MPa; (2) Elongation at break: 398%~412%; (3) Ozone aging test, the test conditions are: elongation 20%, ozone concentration 50ppm, temperature 50℃, humidity 55%: no cracking after 240h; (4) Ultraviolet aging, test conditions: irradiance 0.49W / m 2 Temperature 70℃ for 8 hours; condensation at 50℃ for 4 hours, 45 cycles of test: tensile strength retention rate 95%~96%, elongation at break retention rate 91%~94%.

4. Use of the rubber of claim 3 in the manufacture of tires.

5. A tire comprising the rubber of claim 3, or made from the composition of claim 1.

6. A vehicle or construction machinery comprising the tire of claim 5.

7. A method for preparing the rubber of claim 3, the method comprising the step of refining using the composition of claim 1.

8. The method of claim 7, wherein the method comprises: Ingredient preparation, plasticizing, mixing, and final mixing.

9. The method of claim 7 or 8, comprising the following steps: (1) Preparation of ingredients: Prepare a mixture of natural rubber and EPDM rubber, cut it into wedge-shaped pieces and then dry it; crush and dry the other components in the composition, sieve them, and weigh them according to the proportion for later use; (2) Plasticizing: Set the speed ratio of the front and rear rollers of the open mill to 1:1.5~1:2, adjust the roller gap of the open mill to 0.5~0.6mm, add the mixture of natural rubber and EPDM rubber for plasticizing, and pack it 3 times; (3) Mixing: Adjust the roller gap to 0.8~0.9mm, and add the mixture of natural rubber and EPDM rubber to the mixture for mixing; (4) Final mixing: Add the compounded rubber to the open mill, then add other ingredients for final mixing. After the powder is absorbed, pack it 8 to 10 times to ensure that the ingredients are evenly dispersed. The rubber compound is then sheeted and left to stand for 5-8 hours.

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