A tread rubber composition and its preparation method and application

Abstract

The present invention provides a tread rubber composition, a preparation method and an application thereof, and relates to the technical field of tire manufacturing. The tread rubber composition comprises the following components by weight: 80-120 parts of natural rubber, 20-70 parts of filler, 1-10 parts of activator, 1-10 parts of vulcanizer, and 0.05-1 parts of low eutectic solvent; wherein the low eutectic solvent comprises polyethylene glycol, choline chloride and thiourea. The tread rubber composition of the present invention can effectively achieve high-efficiency vulcanization at low temperature, that is, to achieve the effect of low temperature and long time at low temperature in a short time, and at the same time, the bio-based elastomer is heated for a short time, has a better molecular weight retention rate, can further reduce rolling resistance and improve wear resistance.

Description

Technical Field

[0001] The invention relates to the technical field of tire manufacturing, and in particular to a tread rubber composition and a preparation method and application thereof. Background Art

[0002] Tires are one of the most important parts of a vehicle. During driving, a large amount of energy is lost due to the deformation of the tire itself and the friction between the tire and the ground. This is reflected in the vehicle's fuel and electricity consumption, resulting in increased energy consumption, increased tire heat generation, and early damage. As a load-bearing component of a vehicle, rubber tires have become the largest consumable in the rubber field. The quality of rubber tires is mainly measured by two important indicators: tire rolling resistance and wear resistance. The energy consumption of tires mainly comes from the continuous tensile and compressive forces between the internal structure of the tire caused by the friction between the tread and the road or periodic deformation during driving. The reduction of tire rolling resistance and the improvement of wear resistance are currently the focus of attention and research in the tire industry. The tread is the part that directly contacts the ground during driving. Therefore, how to balance the rolling resistance and wear performance of the tire tread is the focus of current research.

[0003] The process of rubber macromolecules reacting chemically with the cross-linking agent sulfur under heating and cross-linking to form a three-dimensional network structure is called vulcanization. Vulcanization is an important step in the processing of tread rubber. The use of high-temperature vulcanization can shorten the operation time to a certain extent, but it often leads to the problem of scorching on the edge of the product close to the hot plate, and too high a degree of vulcanization will lead to a decrease in the basic mechanical properties and heat generation performance of the tread rubber, thereby reducing the overall durability of the tire. Therefore, the problems existing in low rolling resistance tires require the use of low-temperature vulcanization, but low-temperature vulcanization has the problems of being time-consuming, low efficiency, high manufacturing cost, and poor wear performance of the resulting tread.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a tread rubber composition and a preparation method and application thereof. The tread rubber composition can effectively realize high-efficiency vulcanization at low temperature, that is, achieve the effect of low temperature and long time in a short time at low temperature, and at the same time, the bio-based elastomer is heated for a short time, has a better molecular weight retention rate, can further reduce rolling resistance and improve wear resistance.

[0006] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0007] In a first aspect, the present invention provides a tread rubber composition, wherein the tread rubber composition comprises the following components in parts by weight:

[0008] Natural rubber 80~120 parts

[0009] Filler 20~70 parts

[0010] Activator 1~10 parts

[0011] Vulcanizing agent 1~10 parts

[0012] 0.05~1 part of deep eutectic solvent;

[0013] Wherein, the low eutectic solvent includes polyethylene glycol, choline chloride and thiourea.

[0014] Preferably, the molar ratio of polyethylene glycol, choline chloride and thiourea is (1-3):(1-3):(3-6).

[0015] Preferably, the number average molecular weight of the polyethylene glycol is 200-2000.

[0016] Preferably, the filler includes carbon black and white carbon black.

[0017] Preferably, the mass ratio of the carbon black to white carbon black is (0.8-1.2):1.

[0018] Preferably, the activator comprises stearic acid and zinc oxide.

[0019] Preferably, the mass ratio of stearic acid to zinc oxide is (1-3):(2-5).

[0020] Preferably, the vulcanizing agent comprises sulphur.

[0021] Preferably, the vulcanizing agent also includes an accelerator.

[0022] Preferably, the accelerator comprises 2-thiolbenzothiazole, N -Cyclohexyl-2-benzothiazolesulfenamide, N - any one of tert-butyl-2-benzothiazole sulfenamide, tetramethylthiuram disulfide or dibenzothiazyl disulfide, or a combination of at least two thereof.

[0023] Preferably, the mass ratio of sulfur to accelerator is (1-3):(1-2).

[0024] Preferably, the tread rubber composition further comprises 0 to 5 parts of a silane coupling agent.

[0025] Preferably, the silane coupling agent is bis-[ γ -(triethoxysilyl)propyl]tetrasulfide.

[0026] Preferably, the tread rubber composition further comprises 0 to 5 parts of an antioxidant.

[0027] Preferably, the antioxidant includes N -(1,3-Dimethylbutyl)-N' -phenyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer or N,N'- Any one or a combination of at least two of the xylyl p-phenylenediamines.

[0028] Preferably, the tread rubber composition further comprises 0 to 5 parts of microcrystalline wax.

[0029] In a second aspect, the present invention provides a method for preparing the tread rubber composition according to the first aspect, wherein the preparation method comprises the following steps:

[0030] The natural rubber, filler and activator are mixed for the first time and then discharged to obtain a masterbatch 1;

[0031] The masterbatch 1 is mixed for the second time and then discharged to obtain the masterbatch 2;

[0032] The masterbatch, the vulcanizing agent and the low eutectic solvent are mixed for the third time and then discharged to obtain the tread rubber composition.

[0033] Preferably, during the first mixing process, any one of a silane coupling agent, an antioxidant or a microcrystalline wax or a combination of at least two thereof is added.

[0034] Preferably, the rotation speed of the first mixing is 40-55 rpm.

[0035] Preferably, the first mixing includes: first mixing for 25 to 50 seconds, and then mixing by lifting and pressing the plug for 15 to 30 seconds.

[0036] Preferably, during the first mixing process, the mixing is performed by lifting and pressing the plug until the temperature reaches 150-165° C. for debinding.

[0037] Preferably, the second mixing speed is 25-35 rpm.

[0038] Preferably, the second mixing comprises: first mixing for 15 to 50 seconds, and then mixing by lifting and pressing the plug for 15 to 30 seconds.

[0039] Preferably, during the second mixing process, the mixing is performed at 135-145° C. by lifting and pressing the plug.

[0040] Preferably, the rotation speed of the third mixing is 20-35 rpm.

[0041] Preferably, the third mixing comprises: first mixing for 10 to 50 s, and then mixing by lifting and pressing the plug for 15 to 30 s.

[0042] Preferably, during the third mixing process, mixing is performed at 95-115° C. by lifting and pressing the plug.

[0043] In a third aspect, the present invention provides a use of the tread rubber composition as described in the first aspect in preparing a tire.

[0044] In a fourth aspect, the present invention provides a tire, wherein the tread of the tire comprises the tread rubber composition as described in the first aspect, or the tread rubber composition obtained by the preparation method as described in the second aspect.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The low eutectic solvent composed of polyethylene glycol, choline chloride and thiourea used in the present invention can adjust the vulcanization kinetics. The tread rubber composition prepared therefrom can effectively realize high-efficiency vulcanization at low temperature, achieving the same effect of low-temperature short-time vulcanization and low-temperature long-time vulcanization, that is, the vulcanization temperature can be reduced by 5 to 15°C compared with the existing technology, paving the way for the development of energy-saving and green vulcanization technology.

[0047] (2) The tread rubber composition of the present invention is heated for a short time and thus has a better molecular weight retention rate. The vulcanized rubber produced by using this formula in combination with low-temperature vulcanization has better mechanical strength. In addition, it can also reduce the rolling resistance of the tire tread prepared and improve its wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 This is an appearance diagram of a tire tread prepared by vulcanizing the tread rubber composition provided in Example 1 under the following vulcanization conditions.

[0050] Figure 2 This is an appearance diagram of a tire tread prepared by vulcanizing the tread rubber composition provided in Example 1 under vulcanization condition 2.

[0051] Figure 3 This is an appearance diagram of a tire tread prepared by vulcanizing the tread rubber composition provided in Comparative Example 1 under the following vulcanization conditions.

[0052] Figure 4 This is an appearance diagram of a tire tread prepared by vulcanizing the tread rubber composition provided in Comparative Example 2 under vulcanization condition 2. DETAILED DESCRIPTION

[0053] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0054] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0055] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0056] In a first aspect, the present invention provides a tread rubber composition, wherein the tread rubber composition comprises the following components in parts by weight:

[0057] Natural rubber 80~120 parts

[0058] Filler 20~70 parts

[0059] Activator 1~10 parts

[0060] Vulcanizing agent 1~10 parts

[0061] 0.05~1 part of deep eutectic solvent;

[0062] Wherein, the low eutectic solvent includes polyethylene glycol, choline chloride and thiourea.

[0063] In the present invention, the addition of a low eutectic solvent consisting of polyethylene glycol, choline chloride and thiourea can effectively achieve efficient vulcanization at low temperature, and achieve the effect of low temperature for a long time in a short time at low temperature, and can realize the vulcanization temperature of 5~15°C lower than the existing technology for vulcanization. At the same time, the bio-based elastomer is heated for a short time, has a better molecular weight retention rate, further reduces rolling resistance and improves wear resistance.

[0064] In the tread rubber composition, the amount of natural rubber added is 80 to 120 parts, for example, it can be 80 parts, 82 parts, 84 parts, 86 parts, 88 parts, 90 parts, 92 parts, 94 parts, 96 parts, 98 parts, 100 parts, 102 parts, 104 parts, 106 parts, 108 parts, 110 parts, 112 parts, 114 parts, 116 parts, 118 parts, 120 parts, etc., preferably 95 to 105 parts, and more preferably 100 parts.

[0065] In the tread rubber composition, the added amount of filler is 20 to 70 parts, for example, it can be 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, etc., preferably 30 to 60 parts, and more preferably 40 to 60 parts.

[0066] In the tread rubber composition, the added amount of the activator is 1 to 10 parts, for example, it can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc., preferably 3 to 6 parts.

[0067] In the tread rubber composition, the added amount of the vulcanizer is 1 to 10 parts, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc., preferably 3 to 6 parts.

[0068] In the tread rubber composition, the added amount of the low eutectic solvent is 0.05 to 1 part, for example, it can be 0.05 part, 0.06 part, 0.08 part, 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc., preferably 0.1 to 0.3 part.

[0069] As an optional embodiment of the present invention, the molar ratio of polyethylene glycol, choline chloride and thiourea is (1-3):(1-3):(3-6);

[0070] Among them, polyethylene glycol "1~3" can be, for example, 1, 1.5, 2, 2.5, 3, etc.;

[0071] Among them, choline chloride "1~3" can be, for example, 1, 1.5, 2, 2.5, 3, etc.;

[0072] Among them, thiourea "3~6" can be, for example, 3, 3.5, 4, 4.5, 5.5, 6, etc.

[0073] As an optional embodiment of the present invention, the number average molecular weight of the polyethylene glycol is 200-2000, for example, it can be 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000, etc.

[0074] As an optional embodiment of the present invention, the filler includes carbon black and white carbon black.

[0075] As an optional embodiment of the present invention, the mass ratio of the carbon black to the white carbon black is (0.8-1.2):1, for example, it can be 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, etc.

[0076] As an optional embodiment of the present invention, the activator includes stearic acid and zinc oxide.

[0077] As an optional embodiment of the present invention, the mass ratio of stearic acid to zinc oxide is (1-3):(2-5);

[0078] Among them, stearic acid "1~3" can be, for example, 1, 1.5, 2, 2.5, 3, etc.;

[0079] Among them, zinc oxide "2~5" can be, for example, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc.

[0080] As an optional embodiment of the present invention, the vulcanizing agent includes sulfur.

[0081] As an optional embodiment of the present invention, the vulcanizing agent further includes an accelerator.

[0082] As an optional embodiment of the present invention, the accelerator includes 2-thiolbenzothiazole (accelerator MBT), N -Cyclohexyl-2-benzothiazolesulfenamide (accelerator CZ), N - any one of tert-butyl-2-benzothiazole sulfenamide (accelerator NS), tetramethylthiuram disulfide (accelerator TMTD) or dibenzothiazyl disulfide (accelerator DM) or a combination of at least two thereof.

[0083] As an optional embodiment of the present invention, the mass ratio of sulfur to accelerator is (1-3): (1-2);

[0084] Among them, sulfur "1~3" can be, for example, 1, 1.5, 2, 2.5, 3, etc.;

[0085] Among them, the promoter "1~2" can be, for example, 1, 1.2, 1.4, 1.6, 1.8, 2, etc.

[0086] As an optional embodiment of the present invention, the tread rubber composition also includes 0 to 5 parts of a silane coupling agent, for example, 0.05 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, etc.

[0087] As an optional embodiment of the present invention, the silane coupling agent is bis-[ γ -(triethoxysilyl)propyl]tetrasulfide (Silane Si-69).

[0088] As an optional embodiment of the present invention, the tread rubber composition also includes 0 to 5 parts of an antioxidant, for example, 0.05 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, etc.

[0089] As an optional embodiment of the present invention, the antioxidant includes N -(1,3-Dimethylbutyl)- N' - Phenyl-p-phenylenediamine (antioxidant 4020), 2,2,4-trimethyl-1,2-dihydroquinoline polymer (antioxidant RD) or N,N'- Any one of xylyl paraphenylenediamine (antioxidant DTPD) or a combination of at least two thereof.

[0090] As an optional embodiment of the present invention, the tread rubber composition also includes 0 to 5 parts of microcrystalline wax, for example, 0.05 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, etc.

[0091] As a preferred embodiment of the present invention, the tread rubber composition is composed of the following components in parts by weight:

[0092] Natural rubber 100 parts

[0093] Filler 30~60 parts

[0094] Silane coupling agent 0~5 parts

[0095] Activator 3~6 parts

[0096] 2~5 parts of antioxidant

[0097] 0.5~2 parts of microcrystalline wax

[0098] 3~6 parts of vulcanizing agent

[0099] 0.1~0.3 parts of deep eutectic solvent;

[0100] Wherein, the low eutectic solvent is composed of polyethylene glycol, choline chloride and thiourea in a molar ratio of (1-3):(1-3):(3-6).

[0101] In a second aspect, the present invention provides a method for preparing the tread rubber composition according to the first aspect, the preparation method comprising the following steps:

[0102] The natural rubber, filler and activator are mixed for the first time and then discharged to obtain a masterbatch 1;

[0103] The masterbatch 1 is mixed for the second time and then discharged to obtain the masterbatch 2;

[0104] The masterbatch, the vulcanizing agent and the low eutectic solvent are mixed for the third time and then discharged to obtain the tread rubber composition.

[0105] As an optional embodiment of the present invention, during the first mixing process, any one of a silane coupling agent, an antioxidant or a microcrystalline wax or a combination of at least two thereof needs to be added.

[0106] As a preferred embodiment of the present invention, in the first mixing process, silane coupling agent, antioxidant and microcrystalline wax are further added. That is, the preparation steps of the masterbatch 1 are: mixing natural rubber, filler, silane coupling agent, activator, antioxidant and microcrystalline wax for the first time and then discharging the rubber to obtain the masterbatch 1.

[0107] As an optional embodiment of the present invention, the rotation speed of the first mixing is 40-55 rpm, for example, it can be 40 rpm, 42 rpm, 44 rpm, 46 rpm, 48 rpm, 50 rpm, 52 rpm, 54 rpm, 55 rpm, etc.

[0108] As an optional embodiment of the present invention, the first mixing includes: first mixing for 25 to 50 seconds, and then mixing by lifting and pressing the plug for 15 to 30 seconds.

[0109] As an optional embodiment of the present invention, in the first mixing: the mixing time is 25 to 50 s, for example, it can be 25 s, 26 s, 28 s, 30 s, 32 s, 34 s, 36 s, 38 s, 40 s, 42 s, 44 s, 46 s, 48 ​​s, 50 s, etc.

[0110] As an optional embodiment of the present invention, in the first mixing, the time for mixing by lifting and pressing the plug is 15 to 30 s, for example, it can be 15 s, 16 s, 18 s, 20 s, 22 s, 24 s, 26 s, 28 s, 30 s, etc.

[0111] As an optional embodiment of the present invention, during the first mixing process, the plug is lifted and pressed and mixed to 150-165°C for debinding, for example, it can be 150°C, 151°C, 152°C, 153°C, 154°C, 155°C, 156°C, 158°C, 160°C, 162°C, 164°C, 165°C, etc.

[0112] As an optional embodiment of the present invention, the rotation speed of the second mixing is 25-35 rpm, for example, it can be 25 rpm, 26 rpm, 27 rpm, 28 rpm, 29 rpm, 30 rpm, 31 rpm, 32 rpm, 33 rpm, 34 rpm, 35 rpm, etc.

[0113] As an optional embodiment of the present invention, the second mixing includes: first mixing for 15 to 50 seconds, and then mixing by lifting and pressing the plug for 15 to 30 seconds.

[0114] As an optional embodiment of the present invention, in the second mixing: the mixing time is 15 to 50 s, for example, it can be 15 s, 16 s, 17 s, 18 s, 19 s, 20 s, 21 s, 22 s, 23 s, 24 s, 25 s, 26 s, 28 s, 30 s, 32 s, 34 s, 36 s, 38 s, 40 s, 42 s, 44 s, 46 s, 48 ​​s, 50 s, etc.

[0115] As an optional embodiment of the present invention, in the second mixing: the time for mixing by lifting and pressing the plug is 15 to 30 s, for example, it can be 15 s, 16 s, 18 s, 20 s, 22 s, 24 s, 26 s, 28 s, 30 s, etc.

[0116] As an optional embodiment of the present invention, during the second mixing process, the plug is lifted and pressed and mixed to 135-145°C for degumming, for example, it can be 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, 141°C, 142°C, 143°C, 144°C, 145°C, etc.

[0117] As an optional embodiment of the present invention, the rotation speed of the third mixing is 20~35 rpm, for example, it can be 20 rpm, 21 rpm, 22 rpm, 23 rpm, 24 rpm, 25 rpm, 26 rpm, 27 rpm, 28 rpm, 29 rpm, 30 rpm, 32rpm, 34 rpm, 35 rpm, etc.

[0118] As an optional embodiment of the present invention, the third mixing includes: first mixing for 10 to 50 seconds, and then mixing by lifting and pressing the plug for 15 to 30 seconds;

[0119] As an optional embodiment of the present invention, in the third mixing: the mixing time is 10 to 50 s, for example, it can be 10 s, 11 s, 12 s, 13 s, 14 s, 15 s, 16 s, 17 s, 18 s, 19 s, 20 s, 21 s, 22 s, 23 s, 24 s, 25 s, 26 s, 28 s, 30 s, 32 s, 34 s, 36 s, 38 s, 40 s, 42 s, 44 s, 46 s, 48 ​​s, 50 s, etc.

[0120] As an optional embodiment of the present invention, in the third mixing: the time for mixing by lifting and pressing the plug is 15 to 30 s, for example, it can be 15 s, 16 s, 18 s, 20 s, 22 s, 24 s, 26 s, 28 s, 30 s, etc.

[0121] As an optional embodiment of the present invention, during the third mixing process, the plug lifting and pressing plug mixing is carried out to 95-115°C for degumming, for example, it can be 95°C, 96°C, 98°C, 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 115°C, etc.

[0122] In a third aspect, the present invention provides a use of the tread rubber composition as described in the first aspect in preparing a tire.

[0123] In a fourth aspect, the present invention provides a tire, wherein the tread of the tire comprises the tread rubber composition as described in the first aspect, or the tread rubber composition obtained by the preparation method as described in the second aspect.

[0124] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0125] Example 1

[0126] This embodiment provides a tread rubber composition, which comprises the following components in parts by weight:

[0127]

[0128] The tread rubber composition of this embodiment is prepared by the following steps:

[0129] S1, a masterbatch:

[0130] Start the internal mixer and set the speed to 45 rpm. Add natural rubber, filler, silane coupling agent, activator, antioxidant and microcrystalline wax according to the above ratio, mix for 35 s, then mix for 25 s with the bolt lifted and pressed, mix until the temperature reaches 153°C and discharge the rubber to obtain masterbatch 1.

[0131] S2, second stage masterbatch:

[0132] Start the internal mixer, set the speed to 30 rpm, add masterbatch 1, mix for 30 s, then lift the plug and press the plug to mix for 20 s, lift the plug and press the plug to mix until the temperature reaches 135°C and discharge the glue to obtain masterbatch 2.

[0133] S3. Add sulfur:

[0134] Start the internal mixer and set the speed to 25 rpm. Add the masterbatch II, the vulcanizing agent and the low eutectic solvent according to the above ratio, mix for 20 s, then mix for 25 s with the bolt lifted and pressed, and mix until the temperature reaches 105° C. to obtain the tread rubber composition.

[0135] Example 2

[0136] This embodiment provides a tread rubber composition, which comprises the following components in parts by weight:

[0137]

[0138] The tread rubber composition of this embodiment is prepared by the following steps:

[0139] S1, a masterbatch:

[0140] Start the internal mixer and set the speed to 55 rpm. Add natural rubber, filler, silane coupling agent, activator, antioxidant and microcrystalline wax according to the above ratio, mix for 25 s, then mix for 15 s with the bolt lifted and pressed. Mix until the temperature reaches 150°C and discharge the rubber to obtain masterbatch 1.

[0141] S2, a masterbatch:

[0142] Start the internal mixer, set the speed to 35 rpm, add masterbatch 1, mix for 15 s, then lift the plug and press the plug to mix for 15 s, lift the plug and press the plug to mix until the temperature reaches 135°C and discharge the glue to obtain masterbatch 2.

[0143] S3. Add sulfur:

[0144] Start the internal mixer and set the speed to 35 rpm. Add the masterbatch II, the vulcanizing agent and the low eutectic solvent according to the above ratio, mix for 10 s, then lift the bolt and press the bolt to mix for 15 s, lift the bolt and press the bolt to mix to 95°C and discharge the rubber to obtain the tread rubber composition.

[0145] Example 3

[0146] This embodiment provides a tread rubber composition, which comprises the following components in parts by weight:

[0147]

[0148] The tread rubber composition of this embodiment is prepared by the following steps:

[0149] S1, a masterbatch:

[0150] Start the internal mixer and set the speed to 40 rpm. Add natural rubber, filler, silane coupling agent, activator, antioxidant and microcrystalline wax according to the above ratio, mix for 50 s, then mix for 30 s with the bolt lifted and the bolt pressed. Mix until the temperature reaches 160°C and discharge the rubber to obtain masterbatch 1.

[0151] S2, a masterbatch:

[0152] Start the internal mixer and set the speed to 25 rpm. Add masterbatch 1 and mix for 50 s. Then mix with the plug raised and pressed for 30 s. Mix until the temperature reaches 145°C and discharge the masterbatch 2.

[0153] S3. Add sulfur:

[0154] Start the internal mixer and set the speed to 20 rpm. Add the masterbatch II, the vulcanizing agent and the low eutectic solvent according to the above ratio, mix for 50 s, then mix for 30 s with the bolt lifted and the bolt pressed. Mix until the temperature reaches 115°C and discharge the rubber to obtain the tread rubber composition.

[0155] Example 4

[0156] This embodiment provides a tread rubber composition, which is different from Embodiment 1 only in that the molar ratio of polyethylene glycol, choline chloride and thiourea is 3:3:6, and the contents of other components and the preparation method are consistent with those of Embodiment 1.

[0157] Example 5

[0158] This embodiment provides a tread rubber composition, which is different from Embodiment 1 only in that the molar ratio of polyethylene glycol, choline chloride and thiourea is 2:2:4, and the contents of other components and the preparation method are consistent with those of Embodiment 1.

[0159] Example 6

[0160] This embodiment provides a tread rubber composition, which is different from Embodiment 1 only in that the molar ratio of polyethylene glycol, choline chloride and thiourea is 2.5:2.5:5, and the contents of other components and the preparation method are consistent with those in Embodiment 1.

[0161] Comparative Example 1

[0162] This embodiment provides a tread rubber composition, which is different from Embodiment 1 only in that stearic acid is no longer added to the activator, the zinc oxide content is increased to 5.5 parts, and the contents of other components and the preparation method are consistent with those of Embodiment 1.

[0163] Comparative Example 2

[0164] This embodiment provides a tread rubber composition, which is different from Embodiment 1 only in that stearic acid is no longer added to the activator, the stearic acid content is increased to 5.5 parts, and the contents of other components and the preparation method are consistent with those of Embodiment 1.

[0165] Comparative Example 3

[0166] This embodiment provides a tread rubber composition, which is different from the embodiment 1 only in that the accelerator CZ is no longer added to the activator, the sulfur content is increased to 4 parts, and the contents of other components and the preparation method are consistent with those of the embodiment 1.

[0167] Comparative Example 4

[0168] This embodiment provides a tread rubber composition, which is different from Embodiment 1 only in that the preparation of the second-stage masterbatch S2 is no longer performed, that is, S3 vulcanization is directly performed after the masterbatch 1 is obtained in S1, but in the preparation process of the first-stage masterbatch S1, the mixing time is extended to 50 s, and the mixing time for lifting and pressing the bolts is extended to 30 s. The formula composition and preparation method are consistent with those in Embodiment 1.

[0169] Comparative Example 5

[0170] This comparative example provides a tread rubber composition, which is different from Example 1 only in that no low eutectic solvent is added, and the contents of other components and the preparation method are consistent with those of Example 1.

[0171] Comparative Example 6

[0172] This comparative example provides a tread rubber composition, which is different from Example 1 only in that the low eutectic solvent is replaced by a low eutectic solvent B, which is a combination of a metal chloride (zinc chloride) and different hydrogen donors. The low eutectic solvent B is: polyethylene glycol, zinc chloride and urea in a molar ratio of 2:2:4.5, and the contents of other components and the preparation method are consistent with those in Example 1.

[0173] Comparative Example 7

[0174] This comparative example provides a tread rubber composition, which is different from Example 1 only in that the low eutectic solvent is only choline chloride and thiourea in a molar ratio of 2:4.5, and the contents of other components and the preparation method are consistent with those in Example 1.

[0175] Comparative Example 8

[0176] This comparative example provides a tread rubber composition, which is different from Example 1 only in that the low eutectic solvent is only polyethylene glycol (molecular weight: 600) and choline chloride in a molar ratio of 1:1, and the contents of other components and the preparation method are consistent with those in Example 1.

[0177] Comparative Example 9

[0178] This comparative example provides a tread rubber composition, which is different from Example 1 only in that the low eutectic solvent is only polyethylene glycol (molecular weight: 600) and thiourea in a molar ratio of 2:4.5, and the contents of other components and the preparation method are consistent with those in Example 1.

[0179] Test Example 1

[0180] Test samples: tread rubber compositions provided in Examples 1 to 6, and tread rubber compositions provided in Comparative Examples 1 to 9;

[0181] Test method: Take 5-6 g of the mixed rubber, and analyze the torque-time curve of the test rubber at a vulcanization temperature of 151°C, and determine the vulcanization characteristic parameters: minimum and maximum torque (ML, MH), scorch and positive vulcanization time (t10, t90). Finally, according to t90, press it into a test sample at a pressure of 15 MPa through a flat vulcanizer.

[0182] The CRI in the test results is the sulfur addition index, and its value is calculated as CRI=100 / (tc90-ts1), and the unit is min. -1 , which reflects the speed of the vulcanization of the rubber. The larger the CRI value, the faster the vulcanization speed. Among them, tc90 is the process positive vulcanization time, which is the time required from the beginning of heating to the time when the torque of the rubber increases by 90 units from the minimum value. ts1 is the scorch time, which is the time required from the beginning of heating to the time when the torque of the rubber increases by 0.1Nm from the minimum value.

[0183] In the test results, △M=M H -M L is the difference between the highest and lowest torques, which can reflect the degree of crosslinking (density), where M H is the maximum torque, M L For minimum torque.

[0184] The specific test results are shown in Table 1:

[0185] The actual value is the actual measured value.

[0186] The index form means that the CRI sulfur rate and crosslinking density under the test conditions of 140°C*60min of Comparative Example 1 are assumed to be 100, and the sulfur rates of other embodiments and comparative examples are converted based on this as the basis).

[0187] Table 1

[0188]

[0189] From the perspective of the CRI sulfur index, the vulcanization rate is significantly improved after adding the low eutectic solvent (the difference between Example 1 and Comparative Example 5 is whether the low eutectic solvent is added). Under the test conditions of 140°C*60min, the vulcanization rate is increased by 23%. For Examples 4 to 6, it can be seen that the addition of the low eutectic solvent has different effects on the improvement of the vulcanization rate due to its different ratios. About 0.3 parts of the low eutectic solvent can increase the vulcanization rate by 28-42%; when the temperature is increased by 10°C, the vulcanization rate is increased by about 20%, but the CRI measured in Example 1 at 140°C (with the addition of the low eutectic solvent, the value is 4.81) is faster than the CRI measured in Comparative Example 5 at 150°C (without the addition of the low eutectic solvent, the value is 4.69). This shows that the low eutectic solvent can achieve efficient vulcanization at low temperatures.

[0190] About the application of zinc oxide and stearic acid: zinc oxide is insoluble in rubber, so its active effect cannot be fully exerted when used alone, and must be used with stearic acid to produce zinc soap (complex of stearic acid and zinc) that can be soluble in rubber, and then participate in vulcanization reaction. Stearic acid has an activation effect, and plays an acidic activation role on the double bonds of rubber molecules, thereby accelerating the generation of cross-linked bonds, and can improve the cross-linking density of vulcanized rubber in some vulcanization systems, so zinc oxide and stearic acid are indispensable in the whole vulcanization process, from the perspective of comparative example 1 and comparative example 2, any one of zinc oxide and stearic acid is missing, and the sulfur speed will be greatly slowed down. In addition, when other components are the same, the vulcanization speed is significantly improved after adding a low eutectic solvent, and it may also be due to the fact that zinc oxide participates in the vulcanization mainly as zinc ions, and the low eutectic solvent in the present invention may partially dissolve zinc oxide, improve the zinc ion content in the body, thereby improving the activation efficiency of zinc oxide and stearic acid, and then the vulcanization efficiency of rubber.

[0191] Regarding the selection and application of low eutectic solvents: Low eutectic solvents are mixtures composed of a certain molar ratio of hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD) through the association of hydrogen bonds. The melting point is reduced by charge delocalization, and its melting point is much lower than that of the raw materials. Commonly used hydrogen bond acceptors include choline chloride, tetrabutylammonium bromide, tetrabutylphosphonium bromide, trimethylamine hydrochloride, etc., and hydrogen bond donors include urea, thiourea, ethylene glycol, glycerol, oxalic acid, acetamide, malonic acid, citric acid, etc. Due to the designability of the low eutectic solvent, by changing the types of acceptors and donors and combining them in different proportions, the physicochemical properties of the low eutectic solvent can be changed within a certain range. The physicochemical properties are related to the interaction between anions and cations. The stronger the interaction, the lower the melting point of the mixture. The melting point of the low eutectic solvent is generally lower than 150°C. In the low eutectic solvent of the present invention, the halogen anions in the quaternary ammonium salt (choline chloride) and the hydrogen bond donor can form intermolecular hydrogen bonds. By controlling the distribution ratio of each component of the low eutectic solvent in the present invention to be within the range of polyethylene glycol, choline chloride, The molar ratio of choline to thiourea is (1-3):(1-3):(3-6), which can control the overall melting point to be less than 100°C. During the third mixing process (final mixing stage of adding sulfur), the plug is lifted and pressed to mix at 95-115°C, so that the low eutectic solvent can melt above its melting point at the mixing temperature so that it can be evenly dispersed in the rubber body. Other ratios (Comparative Examples 6-8) cannot meet the above requirements. In addition, if only hydrogen donors (polyethylene glycol and thiourea) are contained in Comparative Example 9 without hydrogen acceptors, the effect cannot be achieved. In addition, the low eutectic solvent will slightly increase the crosslinking density of the tread rubber and the elongation will also be slightly increased, and it has basically no effect on other properties.

[0192] Test Example 2

[0193] Test samples: tread rubber compositions provided in Examples 1 to 6, and tread rubber compositions provided in Comparative Examples 1 to 9;

[0194] Test method:

[0195] Tensile performance test: The tensile mechanical properties of the vulcanized rubber samples were measured using the AI-7000-MT servo-controlled computer system tensile testing machine of the High Speed ​​Rail Testing Instrument Company. In strict accordance with the national standard GB / T 528-2009, 5 samples were punched out for each natural rubber composite material, and the tensile specimen was a dumbbell-shaped specimen with a working area of ​​25 mm × 6 mm.

[0196] Hardness test: According to GB / T 2411-2008 Plastics and hard rubber, the indentation hardness (Shore hardness) is measured using a hardness tester.

[0197] Tear performance test: According to GB-T 529-2008 Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser-shaped, right-angled and crescent-shaped specimens).

[0198] Akron wear performance test uses GT-7012-A AKRON wear tester (GOTECH, Taiwan, China), strictly following the standard GB / T 1689-1998. The sample and the grinding wheel are rubbed at a certain tilt angle and under a certain composite action, and the wear volume or wear index of the sample at a certain mileage is measured. The rotation speed of the rubber wheel shaft is 76r / min±2r / min, and the rotation speed of the grinding wheel shaft is 34r / min±1r / min.

[0199] The loss factor value was measured using a Q800 DMA dynamic thermomechanical analyzer (TA Company, USA; experimental conditions: tensile mode, frequency 20 Hz, 7% ± 2, 0°C to 100°C, every 2°C / min.

[0200] The specific test results under the test conditions of 151℃*30 min are shown in Table 2:

[0201] Table 2

[0202]

[0203] The specific test results under the test condition of 151℃*30 min are shown in Table 3:

[0204] Table 3

[0205]

[0206] In summary, from Table 1 (rheological data) and Table 2 (mechanical property data), the tread rubber composition prepared by the low eutectic solvent adopted in the present invention can effectively realize high-efficiency vulcanization at low temperature, and achieve the effect of low temperature for a long time in a short time at low temperature, and can realize the vulcanization temperature reduced by 5-15°C in the prior art. At the same time, the bio-based elastomer is heated for a short time, has a better molecular weight retention rate, further reduces rolling resistance and improves wear resistance.

[0207] In addition, from Figure 1 and Figure 3 It can be seen from the comparison that Figure 1 The vulcanization temperature is lowered and the tread rubber composition vulcanized with a low eutectic solvent (140℃*30min+low eutectic solvent) is used to complete the vulcanization without pores on the tire tread. Figure 3 (140℃*30min+low eutectic solvent not used) Unused sulfurization is not mature; Figure 2 and Figure 4 It can be seen from the comparison that the tire tread vulcanized with the tread rubber composition using the low eutectic solvent (150℃*15min+low eutectic solvent) with reduced vulcanization time has no pores and completes the vulcanization ( Figure 2), unused (150℃*15min+no eutectic solvent added) immature vulcanization ( Figure 4 ).

[0208] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tread rubber composition, characterized in that: The tread rubber composition comprises the following components by weight: Natural rubber 80~120 parts Filler 20~70 parts Activator 1~10 parts Vulcanizing agent 1~10 parts 0.05~1 part of deep eutectic solvent; Wherein, the deep eutectic solvent comprises polyethylene glycol, choline chloride and thiourea in a molar ratio of (1-3):(1-3):(3-6); Wherein, the activator comprises stearic acid and zinc oxide in a mass ratio of (1-3):(2-5); Wherein, the vulcanizing agent includes sulfur; and the vulcanizing agent also includes an accelerator, and the accelerator includes 2-thiolbenzothiazole, N -Cyclohexyl-2-benzothiazolesulfenamide, N - any one of tert-butyl-2-benzothiazole sulfenamide, tetramethylthiuram disulfide or dibenzothiazole disulfide, or a combination of at least two thereof; The tread rubber composition is prepared by the following preparation method: The natural rubber, filler and activator are mixed for the first time and then discharged to obtain a masterbatch 1; The masterbatch 1 is mixed for the second time and then discharged to obtain the masterbatch 2; wherein the second mixing comprises: mixing for 15 to 50 seconds, and then mixing with the bolt raised and the bolt pressed for 15 to 30 seconds; and during the second mixing, mixing with the bolt raised and the bolt pressed to 135 to 145° C. for discharge; The masterbatch, the vulcanizing agent and the low eutectic solvent are mixed for the third time and then discharged to obtain the tread rubber composition.

2. The tread rubber composition according to claim 1, characterized in that: The number average molecular weight of the polyethylene glycol is 200-2000.

3. The tread rubber composition according to claim 1, characterized in that: The filler includes carbon black and white carbon black; And / or, the mass ratio of the carbon black to the white carbon black is (0.8~1.2):

1.

4. The tread rubber composition according to claim 1, characterized in that: The mass ratio of the sulfur to the accelerator is (1-3):(1-2).

5. The tread rubber composition according to claim 1, characterized in that: The tread rubber composition also includes 0 to 5 parts of a silane coupling agent; And / or, the silane coupling agent is bis-[ γ -(triethoxysilyl)propyl]tetrasulfide; And / or, the tread rubber composition further comprises 0 to 5 parts of an antioxidant; And / or, the antioxidant includes N -(1,3-Dimethylbutyl)- N' -phenyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer or N,N'- Any one or a combination of at least two of xylyl-p-phenylenediamine; And / or, the tread rubber composition further comprises 0 to 5 parts of microcrystalline wax.

6. A method for preparing a tread rubber composition according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: The natural rubber, filler and activator are mixed for the first time and then discharged to obtain a masterbatch 1; The masterbatch 1 is mixed for the second time and then discharged to obtain the masterbatch 2; wherein the second mixing comprises: mixing for 15 to 50 seconds, and then mixing with the bolt raised and the bolt pressed for 15 to 30 seconds; and during the second mixing, mixing with the bolt raised and the bolt pressed to 135 to 145° C. for discharge; The masterbatch, the vulcanizing agent and the low eutectic solvent are mixed for the third time and then discharged to obtain the tread rubber composition.

7. The method for preparing the tread rubber composition according to claim 6, characterized in that: During the first mixing process, any one of a silane coupling agent, an antioxidant or a microcrystalline wax or a combination of at least two thereof needs to be added; And / or, the first mixing speed is 40-55 rpm; And / or, the first mixing includes: firstly mixing for 25 to 50 seconds, and then mixing by lifting and pressing the plug for 15 to 30 seconds; And / or, during the first mixing process, the plug is lifted and pressed to mix until the temperature reaches 150-165° C. for debonding; And / or, the second mixing speed is 25-35 rpm; And / or, the rotation speed of the third mixing is 20-35 rpm; And / or, the third mixing includes: firstly mixing for 10 to 50 seconds, and then mixing by lifting and pressing the plug for 15 to 30 seconds; And / or, during the third mixing process, the mixing is performed by lifting the plug and pressing the plug until the temperature reaches 95-115° C. for debonding.

8. Use of the tread rubber composition according to any one of claims 1 to 5 in preparing a tire.

9. A tire, characterized in that: The tread of the tire comprises the tread rubber composition according to any one of claims 1 to 5, or the tread rubber composition obtained by the preparation method according to any one of claims 6 to 8.

Images