Hydrogenated cardanol-based resin and method for preparing same

Abstract

The present invention provides a hydrogenated cardanol-based resin comprising a copolymer that comprises cardanol and styrene, wherein the copolymer is hydrogenated through a hydrogenation reaction.

Description

Hydrogenated cardanol-based resin and method for manufacturing the same

[0001] The present invention relates to a hydrogenated cardanol-based resin and a method for manufacturing the same. More specifically, the present invention relates to a hydrogenated cardanol-based resin added to a rubber composition for an eco-friendly tire tread and a method for manufacturing the same.

[0002]

[0003] Generally, in addition to the main material, rubber, tires use various types of additives to improve and strengthen the physical properties required for the tire.

[0004] In particular, various petrochemical products are being used to improve energy efficiency in order to enhance fuel economy while considering environmental issues.

[0005] Process oil improves mixing load when mixing rubber and various additives, reduces mixing energy loss when compounding components of tire rubber compositions as a softener, and can improve compatibility between rubber, chemicals, and fillers, which are various materials used in the rubber composition.

[0006] Process oils used in rubber compositions for tires are generally hydrocarbon compounds composed of aromatic, paraffinic, and naphthenic components. Distillate aromatic extract (DAE), which is primarily used as a process oil, contains aromatic components and offers the best compatibility with rubber; however, it is harmful to the environment as it contains an excessive amount of polycyclic aromatic hydrocarbons (PAHs), which are environmentally regulated substances. Consequently, the use of Treated Distillate Aromatic Extract (TDAE) oil has recently increased, but improvements are still needed in terms of carbon dioxide reduction.

[0007] Therefore, there is a need to reduce the content of aromatic components, which are harmful substances in process oils, or to replace them with more environmentally friendly components.

[0008] Korean Published Patent Application No. 10-2012-0077096 is disclosed as background technology for the present invention.

[0009] The objective of the present invention is to provide an eco-friendly hydrogenated cardanol-based resin that can replace DAE or TDAE, which emit PAHs—environmentally regulated substances—in process oils added to rubber compositions for tire treads.

[0010] Another objective of the present invention is to provide a method for manufacturing the above-mentioned hydrogenated cardanol-based resin.

[0011] Another objective of the present invention is to provide a rubber composition for a tire tread comprising a hydrogenated cardanol-based resin.

[0012] The above and other objectives of the present invention can all be achieved by the present invention described below.

[0013] 1. One aspect of the present invention relates to a hydrogenated cardanol-based resin.

[0014] The above hydrogenated cardanol-based resin comprises a copolymer containing cardanol and styrene, and

[0015] The above copolymer is hydrogenated by a hydrogenation reaction.

[0016] 2. In the above 1 embodiment, the copolymer may comprise a copolymer comprising about 65% to 72% by weight of cardanol; and about 28% to 35% by weight of styrene.

[0017] 3. In the above 1 or 2 embodiments, the cardanol-based resin may have an aromatization degree of about 5% to 22%.

[0018] 4. In any one of the embodiments 1 to 3 above, the hydrogenated cardanol-based resin may have a weight-average molecular weight (Mw) of about 800 to 1200, a number-average molecular weight (Mn) of about 600 to 800, and a molecular weight distribution (PDI) of about 1.4 to 1.8.

[0019] 5. Another aspect of the present invention relates to a method for manufacturing a hydrogenated cardanol-based resin.

[0020] The above method for manufacturing a hydrogenated cardanol-based resin comprises: (a) a step of preparing a monomer composition comprising a cardanol monomer, a styrene monomer, and a xylene solvent;

[0021] (b) a step of preparing a reaction product by primary polymerizing the above monomer composition;

[0022] (c) a step of preparing a polymer by secondary polymerizing the above reaction product;

[0023] (d) a step of recovering a cardanol-based resin by reducing the pressure of the polymer; and

[0024] (e) a step of performing a hydrogenation reaction on the cardanol-based resin; is included.

[0025] 6. In the above 5 embodiments, the primary polymerization may be carried out in a continuous stirred tank reactor (CSTR), and the secondary polymerization may be carried out in a plug flow reactor (PFR) placed downstream of the continuous stirred tank reactor.

[0026] 7. In the above 5 or 6 embodiments, the secondary polymerization temperature may be higher than the primary polymerization temperature.

[0027] 8. In any one of the embodiments 5 to 7 above, the volume of the plug flow reactor (PFR) may be larger than the volume of the continuous stirred tank reactor (CSTR).

[0028] 9. In any one of the embodiments 5 to 8 above, the hydrogenation reaction in (e) above can be carried out under a heterogeneous palladium catalyst.

[0029] 10. In any one of the embodiments 5 to 9 above, the hydrogenation reaction in (e) above can be carried out in a fixed-bed reactor (FBR) filled with a catalyst.

[0030] 11. In any one of the embodiments 5 to 9 above, the hydrogenation reaction can be carried out by supplying the raw material to a fixed-bed reactor (FBR) filled with a catalyst at a flow rate of about 20 ml / min to 40 ml / min.

[0031] 12. Another aspect of the present invention relates to a process oil for tire treads.

[0032] The above process oil comprises a hydrogenated cardanol-styrene copolymer having a weight-average molecular weight of about 800 to 1200 and a PDI of about 1.4 to 1.8.

[0033] 13. In the above 12 embodiments, the process oil may have an aromaticity degree of about 5% to 22%.

[0034] 14. Another aspect of the present invention is a rubber composition for a tire tread comprising the above-mentioned hydrogenated cardanol-based resin.

[0035] 15. In the above 15 embodiments, the rubber composition for the tire tread may contain about 10 to 50 parts by weight of a hydrogenated cardanol-based resin per about 100 parts by weight of raw rubber.

[0036] 16. In the above embodiments 14 or 15, the rubber composition for the tire tread may have a wet road braking force measurement (loss factor (tanδ) at 0°C) of about 105 to 121 according to dynamic mechanical analysis at a temperature range of about -80 to 80°C and about 10 Hz, a loss factor (tanδ) of about 88 to 102 according to rolling resistance measurement (60°C), and a wear level of about 113 to 116 according to a wear level measuring instrument.

[0037] The hydrogenated cardanol-based resin according to the present invention is highly environmentally friendly as aromatic components are excluded, and can replace process oil added to rubber compositions for tire treads.

[0038] TDAE, which is primarily used as a process oil for conventional rubber compositions for tire treads, contains an excess amount of polycyclic aromatic hydrocarbons (PAHs), which are aromatic components harmful to the environment. However, hydrogenated cardanol resins are very environmentally friendly because they can replace TDAE by excluding aromatic components.

[0039] A rubber composition for tire treads formulated by selecting a hydrogenated cardanol-based resin as the process oil can exhibit physical properties equivalent to or better than those of conventional TDAE (Treated distillate aromatic extract) process oils, as rolling resistance and road braking force, which are in a trade-off relationship, are controlled to an optimal range.

[0040] FIG. 1 is a process flowchart of a method for manufacturing a hydrogenated cardanol-based resin according to one embodiment of the present invention.

[0041] FIG. 2 is a graph comparing the wet grip, rolling resistance, and wear of a rubber specimen prepared by mixing a hydrogenated cardanol resin prepared according to a method for preparing a hydrogenated cardanol resin according to one embodiment of the present invention with a process oil, and a rubber specimen prepared with a process oil of an aromatic component resin.

[0042]

[0043] The present invention will be described in more detail below with reference to the attached drawings. However, the following drawings are provided merely to aid in understanding the present invention, and the present invention is not limited by the drawings. Furthermore, the shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings are exemplary, and the present invention is not limited to the depicted details.

[0044] Throughout the specification, the same reference numerals refer to the same components. Additionally, in describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the invention.

[0045] Where terms such as 'includes,' 'have,' and 'consists of' are used in this specification, other parts may be added unless 'only' is used. Where a component is expressed in the singular, it includes cases where it includes the plural unless specifically stated otherwise.

[0046] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0047] In this specification, "a to b" indicating a numerical range is defined as "≥a and ≤b".

[0048] In this specification, all numerical ranges include a 95% standard error range.

[0049]

[0050] One aspect of the present invention relates to a hydrogenated cardanol-based resin.

[0051] The above hydrogenated cardanol-based resin includes a copolymer comprising cardanol and styrene.

[0052] Specifically, the above hydrogenated cardanol-based resin comprises a copolymer comprising about 65 to 72 weight% of cardanol and about 28 to 35 weight% of styrene.

[0053] The above hydrogenated cardanol-based resin can be prepared by polymerizing a cardanol monomer and a styrene monomer, and the cardanol monomer can be represented by the following chemical formula 1 using vegetable oil.

[0054] [Chemical Formula 1]

[0055]

[0056] Since the above cardanol monomer is a vegetable oil obtained by naturally extracting cashew nuts from tropical rainforests, it is an eco-friendly material in terms of environment and can reduce manufacturing costs.

[0057] The above cardanol monomer can be copolymerized with a styrene monomer to form a copolymer, and when copolymerized with the above styrene monomer, the hydroxyl group of cardanol is substituted, which has the advantage of being non-toxic and preventing VOC generation.

[0058] The copolymer composed of the above cardanol monomer and styrene monomer can replace DAE or TDAE, which are process oils that are essential in the manufacture of rubber compositions for conventional tire treads.

[0059] The chemical formula of the above styrene monomer is C8H8, and it has a structure in which one hydrogen atom in the benzene ring is substituted with a vinyl group. The above styrene may be produced by dehydrogenation of ethylbenzene using a catalyst such as zinc, iron, chromium, calcium, or magnesium.

[0060] The above styrene can be represented by the following chemical formula 2.

[0061] [Chemical Formula 2]

[0062]

[0063] Since the above styrene has vinyl groups, it is easily polymerized by heat, peroxides, supercatalysts, etc. to become a polymer compound.

[0064] A copolymer is produced by copolymerizing the above cardanol monomer and the above styrene monomer, and the cardanol resin containing the same can exclude aromatic components from tire tread process oil and can be utilized as an environmentally friendly process oil.

[0065] The copolymer may contain about 65 to 72 weight% of cardanol (e.g., 65, 66, 67, 68, 69, 70, 71, or 72 weight%) and about 28 to 35 weight% of styrene (28, 29, 30, 31, 32, 33, 34, or 35 weight%). Preferably, it may contain about 70 weight% of cardanol and about 30 weight% of styrene.

[0066] A copolymer is produced by copolymerization within the above range, and the cardanol resin containing it can replace the process oil in the rubber composition for tire treads.

[0067] The above copolymer is hydrogenated by a hydrogenation reaction.

[0068] Specifically, it may be partially hydrogenated; for example, the degree of aromatization may be lowered by controlling the process conditions of a reactor filled with a hydrogenation catalyst during the manufacturing process. Hydrogenated cardanol-based resins can significantly improve rolling resistance when used in rubber compositions for tire treads.

[0069] In one embodiment, the hydrogenated cardanol-based resin may have an aromaticity of about 5% to 22% (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22%).

[0070] When the degree of aromatization is within the above range, it can not only replace process oils with aromatic components but also improve wet grip and abrasion compared to TDAE.

[0071] The above cardanol petroleum resin has a weight-average molecular weight (Mw) of about 1000 to 1100 (e.g., 1000, 1010, 1020, 1030, 1040, 1050, 1060, 1070, 1080, 1090, or 1100), preferably 1050 to 1100 (1050, 1060, 1070, 1080, 1090, or 1100), and a number-average molecular weight (Mn) of about 600 to 800 (e.g., 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, or 800), preferably about 680 to 730 (e.g., 680, 690, 700, 710, 720, or 730), and a molecular weight distribution (PDI) of about 1.4 to 1.8 (e.g., 1.40, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.70, 1.71, 1.72, 1.73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, or 1.80), and preferably about 1.54 to 1.56.

[0072] When having a weight-average molecular weight, number-average molecular weight, and molecular weight distribution within the above range, it is used as a process oil for a tire tread rubber composition to improve the tire's rolling resistance and road braking force to an optimal range, thereby replacing conventional TDAE and enabling the realization of the effects of the present invention, as well as improving the tire's wear resistance compared to TDAE.

[0073] Another aspect of the present invention relates to a method for manufacturing a hydrogenated cardanol-based resin.

[0074] FIG. 1 is a process flowchart of a hydrogenated cardanol-based resin according to one embodiment of the present invention.

[0075] Referring to FIG. 1, the method for manufacturing a hydrogenated cardanol-based resin comprises: (a) a step of preparing a monomer composition comprising a cardanol monomer, a styrene monomer, and a xylene solvent;

[0076] (b) a step of preparing a reaction product by primary polymerizing the above monomer composition;

[0077] (c) a step of preparing a polymer by secondary polymerizing the above reaction product;

[0078] (d) a step of recovering a cardanol-based resin by reducing the pressure of the polymer; and

[0079] (e) a step of performing a hydrogenation reaction on the cardanol-based resin:

[0080] First, a monomer composition comprising a cardanol monomer, a styrene monomer, and a xylene solvent is prepared (S100).

[0081] For example, about 50 parts by weight of xylene solvent may be mixed with about 50 parts by weight of a raw material comprising a cardanol monomer, a styrene monomer, and combinations thereof, wherein the raw material may comprise about 65% to 72% by weight of cardanol (e.g., 65, 66, 67, 68, 69, 70, 71, or 72% by weight) and about 28% to 35% by weight of styrene (e.g., 28, 29, 30, 31, 32, 33, 34, or 35% by weight).

[0082] A copolymer can be prepared by copolymerizing a cardanol monomer and a styrene monomer within the above range, and the prepared copolymer can be used as a process oil for a rubber composition for tire treads to realize the effects of the present invention. A copolymer that realizes the effects of the present invention can be prepared by controlling the degree of aromatization (Aromaticity), weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (PDI) within the above range.

[0083] The above monomer composition is polymerized first to produce a reaction product (S200).

[0084] Specifically, a reaction product can be produced by continuously supplying a monomer composition to a continuous stirred tank reactor (CSTR) and polymerizing it in one step.

[0085] The above-described continuous stirred tank reactor can continuously polymerize a monomer composition to produce a reaction product, and can effectively improve polymerization efficiency by vigorously stirring the cardanol monomer and styrene monomer. It also has the advantages of being easy to maintain the target temperature during polymerization and suppressing scale formation within the reactor.

[0086] In the above S200, the first stage polymerization can be carried out for about 40 to 50 minutes at about 260°C to 280°C and about 23 bar to 27 bar. The above first stage polymerization can be carried out continuously in a continuous stirred tank reactor, and the reaction product can be produced with a high conversion rate under these conditions.

[0087] A polymer is prepared by secondary polymerization of the above reaction product (S300).

[0088] Specifically, the reaction product can be introduced into a plug flow reactor (PFR) located downstream of the continuous stirred tank reactor and polymerized in two stages to produce a polymer.

[0089] A plug flow reactor can be placed after the above-mentioned continuous stirred tank reactor to enable continuous polymerization.

[0090] The plug flow reactor described above is highly desirable because it discharges reaction products in an amount equal to the amount introduced from the continuous stirred tank reactor, enables uniform molecular weight control, and offers excellent production yield.

[0091] When a plug flow reactor is placed downstream of the above-mentioned continuous stirred tank reactor, the polymer can be manufactured with high efficiency compared to cases where other reactors are placed, and the effects of the present invention can be realized.

[0092] In the above secondary polymerization, the cardanol monomer and the styrene monomer can be copolymerized to produce a cardanol-styrene copolymer.

[0093] In the above S300, secondary polymerization can be carried out for about 60 minutes to 80 minutes under conditions of about 270°C to 290°C and about 23 bar to 27 bar.

[0094] When polymerizing within the above range, the cardanol monomer and the styrene polymer are copolymerized, allowing for the production of a copolymer with a high conversion rate.

[0095] In one embodiment, the secondary polymerization temperature may be higher than the primary polymerization temperature.

[0096] When the above secondary polymerization temperature is high, reactivity is improved, and the polymer conversion rate in the plug flow reactor can be maintained at a high level.

[0097] In one embodiment, the volume of the plug flow reactor (PFR) may be larger than the volume of the continuous stirred tank reactor (CSTR).

[0098] When the volume of the plug flow reactor is larger than the volume of the continuous stirred tank reactor, the polymerization rate can be effectively controlled during continuous polymerization to produce a cardanol-styrene copolymer.

[0099] In one embodiment, polymerization efficiency can be maximized by placing a plug flow reactor (PFR) downstream of the continuous stirred tank reactor (CSTR).

[0100] The above polymer is reduced in pressure to recover the cardanol-based resin (S400).

[0101] Specifically, the polymer can be recovered by reducing the pressure in the plug flow reactor at a temperature of about 250°C to 270°C for about 20 minutes to about 40 minutes.

[0102] A cardanol-styrene copolymer is produced in the above plug flow reactor, and subsequently, the cardanol-styrene copolymer can be recovered by depressurizing the reactor to remove the residual solvent.

[0103] The cardanol-based resin containing the above cardanol-styrene copolymer does not contain aromatic components and can be used as an eco-friendly additive in rubber compositions for tire treads, specifically, process oil can be used.

[0104] When the above cardanol-based resin is used as a process oil, it is very environmentally friendly as it utilizes cardanol, a naturally derived raw material. While cardanol is typically widely used as fuel for power plants, using it as a process oil is more beneficial to the environment and can more effectively reduce carbon emissions. Furthermore, when the above cardanol-based resin is used as a process oil, it can improve the road braking performance and wear resistance of tires, and can demonstrate superior effects compared to TDAE used as a conventional process oil.

[0105] Afterwards, a hydrogenation reaction is performed on the above petroleum resin (S500).

[0106] A hydrogenated cardanol-based resin can be produced by hydrogenating the above cardanol-styrene copolymer.

[0107] Specifically, after the above S400, the above cardanol-styrene polymer is redissolved in a solvent to prepare a raw material, and a hydrogenation reaction can be induced by controlling the flow rate of the raw material and adding hydrogen to a fixed-bed reactor (FBR) filled with a catalyst. Subsequently, the hydrogenated cardanol-based resin can be recovered by reducing the pressure of the product after hydrogenation is completed.

[0108] More specifically, the polymer recovered from the above S400 is redissolved in a solvent to produce a raw material.

[0109] The above polymer is a cardanol-styrene copolymer, and a reaction solution for manufacturing a hydrogenated cardanol-based resin can be prepared by redissolving the polymer in a solvent.

[0110] In one embodiment, the solvent may be cyclohexane.

[0111] The above cyclohexane is synthesized by the hydrogenation reaction of benzene and has a structure in which no further hydrogen can be attached; therefore, even if hydrogen is introduced during the hydrogenation reaction, an exothermic reaction does not occur, and hydrogen waste can be prevented.

[0112] In one embodiment, the hydrogenation reaction can be carried out under a heterogeneous palladium catalyst.

[0113] When the above catalyst is a heterogeneous palladium catalyst, it can be uniformly packed into the catalyst layer within the reactor, and dispersibility during the reaction is improved and a stable hydrogenation reaction can be induced.

[0114] The above heterogeneous palladium catalyst induces a selective hydrogenation reaction that selectively adds hydrogen to either the aromatic double bond or the olefin double bond present in the petroleum resin, and can selectively perform the hydrogenation reaction only on the olefin double bond rather than the aromatic double bond.

[0115] The above catalyst can be charged into the reactor in an amount of about 0.3 to 0.7 parts by weight per about 100 parts by weight of the polymer.

[0116] The above catalyst can enhance the activity of the hydrogenation reaction by significantly improving the activity of the catalyst within the above range.

[0117] In one embodiment, the hydrogenation reaction can be carried out in a fixed-bed reactor filled with a catalyst. Specifically, the flow rate of the raw material can be controlled and hydrogen added to a fixed-bed reactor (FBR) filled with a catalyst to induce a hydrogenation reaction.

[0118] The above fixed-bed reactor has low investment and operating costs, and can perform a hydrogenation reaction by passing a liquid raw material together with hydrogen from top to bottom or from bottom to top inside a reactor containing a catalyst bed filled with a hydrogenation catalyst.

[0119] When a hydrogenation reaction is induced in a fixed-bed reactor filled with the above catalyst, a hydrogenated cardanol-based resin can be produced that has high efficiency of the hydrogenation reaction and can realize the effects of the present invention.

[0120] In one embodiment, the hydrogenation reaction can be carried out by supplying the raw material to a fixed-bed reactor filled with a catalyst at a flow rate of about 20 to 40 ml / min (e.g., 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 ml / min).

[0121] When the raw material flow rate is determined within the above range, the hydrogenation reaction can be effectively induced, and the effects of the present invention can be realized.

[0122] The above hydrogen can be supplied at a rate of about 3 NLPM to 5 NLPM (Normal Liter Per Minute).

[0123] The above hydrogen can be supplied within the above range to induce a hydrogenation reaction.

[0124] The above reactor is depressurized to recover the product after hydrogenation is completed.

[0125] The residual solvent can be removed through the above reduced pressure, and the hydrogenated cardanol-based resin may include a hydrogenated cardanol-styrene copolymer.

[0126] When the above hydrogenated cardanol-based resin is used as a process oil in a rubber composition for tire treads, not only can road surface braking power and wear resistance be significantly improved, but the rolling resistance of the tire can also be improved to be equal to or greater than that of TDAE.

[0127] The above-mentioned pressure may be applied to the product at a temperature range of about 130°C to 170°C for about 20 to 30 minutes. For example, it may be applied at about 150°C for about 30 minutes.

[0128] Hydrogenated cardanol-based resin can be recovered very effectively when the pressure is reduced within the above range.

[0129] The hydrogenated cardanol resin produced by the above method for producing hydrogenated cardanol resin can replace the process oil used in rubber compositions for tire treads.

[0130] Another aspect of the present invention provides a process oil for tire treads.

[0131] The above process oil for tire treads has a weight-average molecular weight of about 800 to 1200 (e.g., 800, 810, 820, 830, 840, 850, 860, 870, 880, 890, 900, 910, 920, 930, 940, 950, 960, 970, 980, 990, 1000, 1010, 1020, 1030, 1040, 1050, 1060, 1070, 1080, 1090, 1100, 1110, 1120, 1130, 1140, 1150, 1160, 1170, 1180, It may include a hydrogenated cardanol-based resin having a PDI of about 1.4 to 1.8 (e.g., 1.4, 1.5, 1.6, 1.7, or 1.8) and 1190 or 12000.

[0132] In one embodiment, the process oil may have a degree of aromaticity of about 5% to 22% (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22).

[0133] The degree of aromaticity of the above process oil can improve compatibility with polymers within the above range. Specifically, since the aromatic content of rubbers mainly used in tires is around 15% and the aromatic content in the overall tire compound is around 12%, the process oil can exhibit excellent compatibility with rubber and tire compounds in terms of aromatic content within the above range.

[0134] Another aspect of the present invention relates to a rubber composition for a tire tread comprising the above-mentioned hydrogenated cardanol-based resin as a process oil.

[0135] The above rubber composition for tire treads comprises raw rubber and the above hydrogenated cardanol-based resin, and accordingly exhibits high braking performance and fuel efficiency.

[0136] The above hydrogenated cardanol-based resin is included in the rubber composition for tire treads to further improve the adhesive performance between rubbers, and improves the physical properties of the rubber composition for tire treads by improving the mixability, dispersibility, and processability of fillers and other additives.

[0137] In particular, the above-mentioned hydrogenated cardanol-based resin satisfies the range of monomer composition and degree of aromatization described above, thereby exhibiting excellent compatibility with raw rubber and additives, and can minimize the increase in rolling resistance while providing improved braking performance due to excellent adhesion.

[0138] The above raw rubber is not particularly limited as long as it has an olefinic double bond (carbon-carbon double bond), and natural rubber, synthetic rubber, or a mixture thereof may be used.

[0139] For example, the above raw rubber may be one or more selected from the group consisting of natural rubber, butadiene rubber, nitrile rubber, silicone rubber, isoprene rubber, styrene-butadiene rubber (SBR), isoprene-butadiene rubber, styrene-isoprene-butadiene rubber, acrylonitrile-butadiene rubber (NBR), ethylene-propylene-diene rubber, butyl halogenated rubber, isoprene halogenated rubber, isobutylene copolymer, chloroprene rubber, butyl rubber, and isobutylene-p-methylstyrene halogenated rubber.

[0140] In one embodiment, the rubber composition for a tire tread may contain the hydrogenated cardanol-based resin in an amount of about 10 to 50 (10, 20, 30, 40, or 50) parts by weight per about 100 parts by weight of raw rubber. Preferably, it may contain about 20 to 50 parts by weight, and more preferably about 20 to 30 parts by weight. If the content of the cardanol petroleum resin is less than about 10 parts by weight per about 100 parts by weight of raw rubber, it is difficult to ensure dispersibility, processability, and braking characteristics, and if it exceeds about 50 parts by weight, although the braking characteristics become excellent, there may be a problem where the rolling resistance becomes too high.

[0141] The above rubber composition for tire treads may further include one or more selected from the group consisting of fillers, silane coupling agents, anti-aging agents, softeners, vulcanizing agents, vulcanization accelerators, and vulcanization accelerating aids.

[0142] The above filler is added to increase the durability and heat resistance of the tire and to improve chipping resistance, cutting resistance, and wear resistance, and, for example, carbon black and / or silica may be used.

[0143] The above carbon black has a nitrogen adsorption specific surface area per gram (N2SA) of approximately 30 to 300 m² 2It can be / g, and the DBP (n-dibutyl phthalate) oil absorption amount can be about 60 to 180 cc / 100g.

[0144] The nitrogen adsorption specific surface area of ​​the above carbon black is approximately 300 m² 2 If it exceeds / g, the processability of the rubber composition for tires may become unfavorable, and about 30 m 2 If it is less than / g, the reinforcing performance by the carbon black filler may be disadvantageous. In addition, if the DBP oil absorption amount of the carbon black exceeds about 180cc / 100g, the processability of the rubber composition may be reduced, and if it is less than about 60cc / 100g, the reinforcing performance by the carbon black filler may be disadvantageous.

[0145] The above carbon black may be included in an amount of about 1 to 50 parts by weight, preferably about 5 to 30 parts by weight, per about 100 parts by weight of the raw rubber. If the content of the carbon black is less than about 1 part by weight, the reinforcing performance by the carbon black filler may be reduced, and if it exceeds about 50 parts by weight, the processability of the rubber composition may become unfavorable.

[0146] The above silica has a nitrogen adsorption specific surface area per gram (N2SA) of approximately 100 to 180 m² 2 / g, and the specific surface area for CTAB (cetyl trimethyl ammonium bromide) adsorption is approximately 110 to 170 m² 2 It may be / g, but the present invention is not limited thereto.

[0147] The nitrogen adsorption specific surface area of ​​the above silica is approximately 100 m² 2 If it is less than / g, the reinforcing performance by the silica filler may be unfavorable, and approximately 180 m 2 If it exceeds / g, the processability of the rubber composition may be adverse. In addition, the CTAB adsorption specific surface area of ​​the silica is approximately 110 m² 2If it is less than / g, the reinforcing performance by the silica filler may be unfavorable, and approximately 170 m 2 If it exceeds / g, the processability of the rubber composition may be adverse.

[0148] The silica may be included in an amount of about 10 to 150 parts by weight per about 100 parts by weight of the raw rubber, and preferably in an amount of about 50 to 100 parts by weight. If the content of the silica is less than about 10 parts by weight, the improvement in the strength of the rubber is insufficient and the fuel efficiency of the tire may be reduced, and if the content of the silica exceeds about 150 parts by weight, the wear performance may be reduced.

[0149] Meanwhile, when using the above silica, a silane coupling agent may be further included for the formulation of the silica. The above silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxy-ethoxy)silane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis(3-(triethoxysilyl)propyl)disulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-(triethoxysilyl)propyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-Mercaptopropyltriethoxysilane, 2-Mercaptoethyltrimethoxysilane, 2-Mercaptoethyltriethoxysilane, 3-Trimethoxysilylpropyl-N,N-Dimethylthiocarbamoyltetrasulfide, 3-Triethoxysilylpropyl-N,N-Dimethylthiocarbamoyltetrasulfide, 2-Triethoxysilylethyl-N,N-Dimethylthiocarbamoyltetrasulfide, 3-Trimethoxysilylpropylbenzothiazolyltetrasulfide, 3-Triethoxysilylpropylbenzolyltetrasulfide, 3-Triethoxysilylpropylmethacrylate monosulfide, 3-Trimethoxysilylpropylmethacrylate monosulfide, Bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-Mercaptopropyldimethoxymethylsilane, Examples include dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide and dimethoxymethylsilylpropylbenzothiazolyltetrasulfide, which are used alone or in a mixture of two or more types, and preferably bis(3-(triethoxysilyl)propyl)tetrasulfide can be used.

[0150] The above silane coupling agent may be included in an amount of about 1 to 15 parts by weight or about 5 to 10 parts by weight per about 100 parts by weight of the raw rubber to improve the dispersibility of the silica. If the content of the silane coupling agent is less than 1 part by weight, the improvement in the dispersibility of the silica is insufficient, which may result in reduced processability of the rubber or reduced fuel efficiency. If it exceeds about 20 parts by weight, the interaction between the silica and the rubber is too strong, which may result in excellent fuel efficiency but significantly reduced braking performance.

[0151] The above anti-aging agent is an additive used to stop the chain reaction in which the tire is auto-oxidized by oxygen. As the above anti-aging agent, any one selected from the group consisting of amine-based, phenol-based, quinoline-based, imidazole-based, metal carbamate salts, waxes, and combinations thereof may be appropriately selected and used.

[0152] As the above amine-based anti-aging agent, any one selected from the group consisting of N-phenyl-N'-(1,3-dimethyl)-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine, N-phenyl-N'-cyclohexyl p-phenylenediamine, N-phenyl-N'-octyl-p-phenylenediamine, and combinations thereof may be used. As the above phenol-based anti-aging agent, any one selected from the group consisting of phenolic 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-isobutylidene-bis(4,6-dimethylphenol), 2,6-di-t-butyl-p-cresol, and combinations thereof may be used. As the above-mentioned quinoline-based anti-aging agent, 2,2,4-trimethyl-1,2-dihydroquinoline and derivatives thereof may be used, specifically, any one selected from the group consisting of 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 6-anilino-2,2,4-trimethyl-1,2-dihydroquinoline, 6-dodecyl-2,2,4-trimethyl-1,2-dihydroquinoline, and combinations thereof may be used. Preferably, waxy hydrocarbon may be used as the above-mentioned wax.

[0153] Considering conditions such as having high solubility in rubber, low volatility, being inert to rubber, and not inhibiting vulcanization in addition to anti-aging action, the above anti-aging agent may be included in an amount of about 1 to 10 parts by weight per about 100 parts by weight of the raw rubber.

[0154] The above-mentioned softener is added to impart plasticity to the rubber to facilitate processing, or to reduce the hardness of vulcanized rubber, and may use petroleum-based oils, vegetable oils, and combinations thereof. Specifically, as a softener, TDAE (treated distillate aromatic extracts) oil, MES (mild extraction solvate) oil, RAE (residual aromatic extract) oil, or heavy naphthenic oil may be used, and preferably, TDAE oil may be used.

[0155] It is preferable to use the above softener in an amount of about 1 to 20 parts by weight per about 100 parts by weight of the raw rubber in terms of processability.

[0156] As the above vulcanizing agent, a sulfur-based vulcanizing agent may be preferably used. As the above sulfur-based vulcanizing agent, inorganic vulcanizing agents such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), and colloidal sulfur may be used. Specifically, as the above sulfur-based vulcanizing agent, elemental sulfur or a vulcanizing agent that produces sulfur, such as amine disulfide or polymeric sulfur, may be used.

[0157] It is desirable for the above vulcanizing agent to be included in an amount of about 0.5 parts by weight or more, or about 1.0 parts by weight or more, and about 4.0 parts by weight or less, or about 3.0 parts by weight or less, per about 100 parts by weight of the above raw rubber, in order to secure an appropriate vulcanization effect and stability of the raw rubber.

[0158] The above vulcanization accelerator is an accelerator that accelerates the vulcanization rate or promotes a delaying effect during the initial vulcanization stage.

[0159] Examples of the above vulcanization accelerators include thiuram-based accelerators such as trimethylthiuram monosulfide, tetramethylthiuram disulfide, and tetraethylthiuram disulfide; thiazole-based accelerators such as 2-mercaptobenzothiazole and dibenzothiazyl disulfide; sulfenamide-based accelerators such as N-cyclohexyl-2-benzothiazylsulfenamide and N-oxydiethylene-2-benzothiazolylsulfenamide; aldehyde-amine-based accelerators such as n-butylaldehyde-aniline condensation products and butylaldehyde-monobutylamine condensation products; aldehyde-ammonia-based accelerators such as hexamethylenetetramine; thiourea-based accelerators such as thiocarbanilide; and guanidine-based accelerators such as 1,3-diphenylguanidine. When these vulcanization accelerators are incorporated, one type may be used alone or two or more types may be used in combination. For example, 1,3-diphenylguanidine (DPG) and N-cyclohexyl-2-benzothiazylsulfenamide (CBTS) can be used as vulcanization promoters.

[0160] It is preferable to use the above vulcanization accelerator in an amount of about 0.1 to 10 parts by weight per about 100 parts by weight of raw rubber in terms of improving physical properties.

[0161] The above vulcanization accelerating agent is used in combination with the above vulcanization accelerator to further enhance the accelerating effect.

[0162] Examples of the above vulcanization accelerating agents include metal oxides such as zinc oxide and magnesium oxide, metal hydroxides such as calcium hydroxide, metal carbonates such as zinc carbonate and basic zinc carbonate, fatty acids such as stearic acid and oleic acid, aliphatic metal salts such as zinc stearate and magnesium stearate, amines such as n-butylamine and dicyclohexylamine, ethylene dimethacrylate, diallyl phthalate, N,Nm-phenylenedimaleimide, trialyl isocyanurate, and trimethylolpropane trimethacrylate. When these vulcanization agents are used, one type may be used alone, or two or more types may be used in combination.

[0163] It is preferable to use the above vulcanization accelerating agent in an amount of about 0.1 to 10 parts by weight per about 100 parts by weight of raw rubber in terms of improving physical properties.

[0164] Meanwhile, the above rubber composition for tire treads may further include various additives used in the rubber industry, such as vulcanization retardants, release agents, process oils, plasticizers, etc.

[0165] The above rubber composition for tire treads can be prepared by mixing each of the above-described components using a mixing machine such as a plastomill, a Banbury mixer, a roll, or an internal mixer.

[0166] The rubber composition for a tire tread manufactured by the above method can be used as a material for constituting the tread portion (and the cap portion including the tread portion) that contacts the road surface, and furthermore, can be used for various rubber components constituting the tire, such as the sidewall, sidewall insert, apex, chafer, wire coat, or inner liner.

[0167] A tire manufactured using the above rubber composition for tire treads has high grip, excellent driving stability and braking performance, and low rolling resistance, making it suitable for use as a fuel-efficient and high-performance tire.

[0168] In one embodiment, the rubber composition for the tire may have a loss factor (tanδ) of about 105 to 121 according to a wet road braking force measurement (0°C) at a temperature range of about -80 to 80°C and about 10 Hz according to dynamic mechanical analysis, a dynamic loss factor (tanδ) of about 88 to 102 according to a rolling resistance measurement (60°C), and a wear factor of about 113 to 116 according to a wear meter.

[0169] Within the above range, the road surface braking force and tire rolling resistance, which are in a trade-off relationship, are implemented in an optimal range to exhibit physical properties equivalent to or better than those of conventional TDAE, thereby realizing the effects of the present invention, and within the above range, wear resistance is improved to exhibit very high wear resistance.

[0170]

[0171] Hereinafter, preferred embodiments are presented to aid in understanding the present invention; however, the following embodiments are merely illustrative of the invention and the scope of the invention is not limited to the following embodiments.

[0172]

[0173] Preparation Example

[0174] A monomer composition was prepared by mixing 1960g of cardanol monomer (80% purity) and 840g of styrene monomer in 700g of xylene solvent.

[0175] While continuously supplying the above monomer composition to a continuous stirred tank reactor (hereinafter 'CSTR', internal volume: 0.416 L), a first-stage polymerization was carried out for 42 minutes under conditions of a temperature of 270°C and a pressure of 25 bar.

[0176] While continuously feeding the reaction product from the first stage polymerization into a plug flow reactor (hereinafter 'PFR', internal volume: 0.590 L) connected to the CSTR, a second stage polymerization was carried out for 64 minutes under conditions of a temperature of 280°C and a pressure of 25 bar.

[0177] The polymerization-completed product was subjected to reduced pressure at 260°C for 30 minutes to recover a cardanol-based resin containing a cardanol-styrene copolymer.

[0178]

[0179] Example 1

[0180] The cardanol-styrene copolymer prepared in the preparation example was redissolved in cyclohexane and then supplied to a 1.5 m long fixed-bed reactor filled with a heterogeneous palladium catalyst (0.5 wt% based on 100 wt% of cardanol petroleum resin). A hydrogenation reaction was carried out under conditions of a reaction temperature of 250°C, a reaction pressure of 100 bar, a raw material flow rate of 40 ml / min, and a hydrogen flow rate of 4 NLPM to produce a partially hydrogenated resin. The hydrogenated product was reduced in pressure at 150°C for 30 minutes to recover the hydrogenated cardanol-based resin.

[0181]

[0182] Example 2

[0183] The cardanol-styrene copolymer prepared in the preparation example was hydrogenated in the same manner as in Example 1, but a hydrogenated cardanol-based resin was prepared at a raw material flow rate of 30 ml / min. The hydrogenated product was subjected to reduced pressure at 150°C for 30 minutes to recover the hydrogenated cardanol-based resin.

[0184]

[0185] Example 3

[0186] The cardanol-styrene copolymer prepared in the preparation example was hydrogenated in the same manner as in Example 1, but with a raw material flow rate of 20 ml / min to produce a hydrogenated cardanol-based resin. The hydrogenated product was subjected to reduced pressure at 150°C for 30 minutes to recover the hydrogenated cardanol-based resin.

[0187]

[0188] Comparative Example 1

[0189] TDAE_STD, which is used as a process oil for tire rubber compositions, was prepared.

[0190]

[0191] Comparative Example 2

[0192] Cardanol that was not copolymerized with styrene was prepared.

[0193]

[0194] Experimental Example 1

[0195] The degree of aromatization was measured for the hydrogenated cardanol-based resins prepared in Examples 1 to 3 and the products of Comparative Examples 1 and 2.

[0196] The weight-average molecular weight (Mw), number-average molecular weight (Mn), and average molecular weight (Mz) of polystyrene were determined through gel permeation chromatography (GPC; Infinity1260) analysis. Additionally, PDI (Mw / Mn) was calculated as the ratio of Mn to the measured Mw.

[0197] Specifically, the hydrogenated cardanol-based resins of Examples 1 to 3 were dissolved in tetrahydrofuran to a concentration of 5 wt%, and 10 µl was injected into the GPC. Tetrahydrofuran was used as the mobile phase of the GPC and introduced at a flow rate of 1 mL / min, and the analysis was performed at 35°C. The column consisted of one Guard column and three PL gels connected in series: PL gel 5 µm 500A, PL gel 5 µm 100A, and PL gel 5 µm 50A. A refractive index detector (RID) was used as the detector, and measurements were taken at 35°C.

[0198] In the case of the manufacturing example, the weight-average molecular weight (Mw) was found to be 1121, the number-average molecular weight (Mn) was 729, and the PDI (Mw / Mn) was 1.54.

[0199] To determine whether the process oil of the rubber composition for tire treads could be replaced, the degree of aromatization of the hydrogenated cardanol-based resins of Examples 1 to 3 was measured.

[0200] Aromaticity (%) was determined by dissolving the resin in the solvent CDCl3 at a concentration of 2.5 wt%, performing 1H-NMR analysis (600 MHz), and calculating the aromaticity from the ratio of the number of protons in the aromatic region to the total number of protons in the polymer as shown in Equation 1 below.

[0201] [Mathematical Formula 1]

[0202]

[0203] In the above mathematical formula 1, Ar A is the number of protons obtained from the area ratio of hydrogen peaks bonded to aromatic hydrocarbons appearing in the aromatic region, specifically in the 6.0 to 9.0 ppm region, and O A is the number of protons obtained from the area ratio of hydrogen peaks appearing in the olefin region, specifically in the 4.0 to 6.0 ppm region, and Al A is the number of protons obtained from the ratio of the area of ​​hydrogen peaks bonded to aliphatic hydrocarbons, which appears in the aliphatic region, specifically in the 0.1 to 4.0 ppm region.

[0204] In the case of the manufacturing example, it was confirmed to be 21.50%, Example 1 12.31%, Example 2 8.50%, and Example 3 5.41%, and in particular among the hydrogenated cardanol resins, Example 3 showed aromatization equivalent to 4.96% of Comparative Example 1 (TDAE).

[0205]

[0206] Experimental Example 2

[0207] It was confirmed whether the process oil in the rubber composition for tire treads could be replaced using the hydrogenated cardanol-based resin of the example.

[0208] Compounding was performed to manufacture a rubber composition for tire treads, specifically using 84.60 g of styrene-butadiene rubber (SBR, Kumho Petrochemical 5251H) and 28.20 g of neodymium butadiene rubber (Kumho Petrochemical NdBR40) as raw rubbers, 112.87 g of silica (EVONIK Ultrasil VN3 GR) and 5.64 g of carbon black (OEC N220) as fillers, 11.29 g of bis(3-(triethoxysilyl)propyl)tetrasulfide (TESPT, EVONIK Si-69) as a silane coupling agent, 1.69 g of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) as an anti-aging agent, and 1,3-diphenylguanidine (DPG) as a vulcanization accelerator A rubber composition for a tire tread was prepared by adding 2.11 g of N-cyclohexyl-2-benzothiazylsulfenamide (CBTS) 1.47 g, 3.39 g of ZnO and 2.26 g of stearic acid as vulcanization accelerators, 1.58 g of sulfur as a vulcanizing agent, 19.75 g of TDAE (Treated Distillate Aromatic Extracts) and 1.13 g of wax as softeners, and 22.57 g of petroleum resins of Examples 1 to 4, and compounding in a Brabender mixer.

[0209] Subsequently, test rubber specimens were prepared by vulcanizing at 160°C for about 20 minutes. The vulcanization time was set to the t90 value of the MDR (Moving die rheometer).

[0210] Rubber specimens were prepared using hydrogenated cardanol-based resins according to Examples 1 to 3 as process oils, and petroleum resins of Comparative Example 1 (TDAE) and Comparative Example 2 (cardanol) were used as process oils among the additives.

[0211] Preparation Example Example 1 Example 2 Example 3 Comparative Example 1 (TDAE) Comparative Example 2 (Cardanol) CSTR(°C) 270 270 270 270 -- PFR(°C) 280 280 280 280 -- Cardanol 70% 70% 70% 70% -100% Styrene 30% 30% 30% 30% -- Aromaticity 21.50% 12.31% 8.50% 5.41% 4.96% 12.54% Mw 112 11099 1074 1051 703 478 Mn 729 704 697684 693 480 PDI 1.54 1.56 1.54 1.54 0.842 1.002

[0212] Table 1 above shows the reactor temperature conditions and the results of measuring the cardanol and styrene content, degree of aromatization, weight-average molecular weight, number-average molecular weight, and molecular weight distribution of the hydrogenated cardanol-based resins of Preparation Example and Examples 1 to 3.

[0213] Referring to Table 1 above, it was confirmed that the weight-average molecular weight of the specimens of Examples 1 to 3, in which cardanol-styrene copolymer was used as the process oil, was 1051 to 1099, the number-average molecular weight was 684 to 704, and the molecular weight distribution was 1.54 to 1.56.

[0214] It was confirmed that the weight-average molecular weight, number-average molecular weight, and molecular weight distribution changed depending on the reactor conditions.

[0215] It was confirmed that if the molecular weight is too large, it is difficult to function as a process oil, and if the polymerization temperature is kept low under process conditions, the molecular weight increases due to the styrene monomer, and since the polymerization temperature is low, there is a problem of the overall process yield decreasing. The molecular weight of each specimen was a result of the process conditions according to the example, and it was confirmed that maintaining the weight-average molecular weight at 1200 or less, the number-average molecular weight at 800 or less, and the molecular weight fraction at 1.4 to 1.8 represents the optimal condition for commercial production yield.

[0216]

[0217] Experimental Example 3

[0218] For the manufactured rubber specimens, the loss factor (Tan δ) related to wet grip and rolling resistance was measured at a temperature range of -80 to 80°C and 10 Hz using Dynamic Mechanical Analysis (Model: TA-DMA Q800).

[0219] The degree of wear was measured using an abrasion tester (Abrasion Tester (Heinrich Bareiss Prufgeratebau GmbH)) according to the following mathematical formula 2.

[0220] [Mathematical Formula 2]

[0221] (Mass before wear) / (Mass after wear) = Wear loss

[0222] FIG. 2 is a graph comparing the wet grip, rolling resistance, and wear of a rubber specimen prepared with a process oil of cardanol petroleum resin prepared according to a method for preparing cardanol petroleum resin according to one embodiment of the present invention and a rubber specimen prepared with a process oil of an aromatic component resin.

[0223] Tanδ@ 0℃ Wet grip Tanδ@ 60℃ Rolling resistance Wear rate Manufacturing Example 10689115 Example 110796114 Example 211596114 Example 3121102113 Comparative Example 1100100100 Comparative Example 2988995

[0224] Table 2 above shows the road surface braking force, rolling resistance, and wear in Examples 1 to 3.

[0225] Referring to Table 2 and Figure 2 above, data for Manufacturing Example and Examples 1 to 3 were prepared based on the physical properties of Comparative Example 1 (TDAE), which is used as a conventional process oil.

[0226] Although a lower rolling resistance value indicates improved fuel efficiency, to enhance intuitiveness, the reciprocal was taken, so a higher value indicates superior rolling resistance characteristics. Similarly, regarding wear, a lower value implies longer tire life, but to enhance intuitiveness, the reciprocal was taken, so a higher value indicates superior tire life. For all scores representing physical properties on the graph, a higher value indicates superior performance.

[0227] Referring to Table 2 and Figure 2, the conventional Cardanol of Comparative Example 2 showed inferior road braking performance, rolling resistance, and wear resistance. On the other hand, Example 1 showed excellent road braking performance and wear resistance.

[0228] Meanwhile, in tire formulations, road braking performance and rolling resistance are in a trade-off relationship, so it is important to identify the optimal conditions that improve both properties simultaneously; as for wear, wear determines tire lifespan, and the higher the wear, the longer the tire lasts.

[0229] Examples 1 to 3 showed that rolling resistance improved according to the degree of hydrogenation, and in particular, in the case of the hydrogenated cardanol petroleum resin in Example 3, when the raw material flow rate of the reactor was adjusted to 20 ml / min, the loss coefficient (60°C) tanδ increased to 102, confirming that it showed superior road surface braking power and increased wear compared to Comparative Example 1.

[0230]

[0231] Accordingly, the present invention provides a cardanol-based resin comprising a cardanol and styrene copolymer, and the cardanol-based resin can replace the process oil in rubber compositions for tire treads. The tire manufactured accordingly is not only highly environmentally friendly compared to DAE (distillate aromatic extract) or TDAE, which contain a large amount of conventional aromatic components and cause environmental problems when used as process oils, but also possesses optimal performance capable of exhibiting physical properties equivalent to or better than DAE by controlling the road braking force and rolling resistance—which are in a trade-off relationship—by lowering the degree of aromatization through a hydrogenation reaction.

[0232]

[0233] The present invention has been described above with reference to embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the invention.

[0234]

Claims

1. A copolymer comprising cardanol and styrene, and The above copolymer is one that has been hydrogenated by a hydrogenation reaction, Hydrogenated cardanol resin.

2. The copolymer of claim 1 comprises about 65% to 72% by weight of cardanol; and about 28% to 35% by weight of styrene; a hydrogenated cardanol-based resin.

3. The hydrogenated cardanol resin according to claim 1, wherein the hydrogenated cardanol resin has an aromatization degree of about 5% to 22%.

4. The hydrogenated cardanol resin according to claim 1, wherein the hydrogenated cardanol resin has a weight-average molecular weight (Mw) of about 800 to 1200, a number-average molecular weight (Mn) of about 600 to 800, and a molecular weight distribution (PDI) of about 1.4 to 1.

8.

5. (a) A step of preparing a monomer composition comprising a cardanol monomer, a styrene monomer, and a xylene solvent; (b) a step of preparing a reaction product by primary polymerizing the above monomer composition; (c) a step of preparing a polymer by secondary polymerizing the above reaction product; (d) a step of recovering a cardanol-based resin by reducing the pressure of the polymer; and (e) a step of performing a hydrogenation reaction on the above cardanol-based resin; comprising, Method for manufacturing hydrogenated cardanol-based resin.

6. A method for manufacturing a hydrogenated cardanol-based resin according to claim 5, wherein the first polymerization is performed in a continuous stirred tank reactor (CSTR) and the second polymerization is performed in a plug flow reactor (PFR) located downstream of the continuous stirred tank reactor.

7. A method for manufacturing a hydrogenated cardanol-based resin according to claim 5, wherein the secondary polymerization temperature is higher than the primary polymerization temperature.

8. A method for manufacturing a hydrogenated cardanol-based resin according to claim 6, wherein the volume of the plug flow reactor (PFR) is larger than the volume of the continuous stirred tank reactor (CSTR).

9. A method for producing a hydrogenated cardanol-based resin according to claim 5, wherein the hydrogenation reaction in (e) above is performed under a heterogeneous palladium catalyst.

10. A method for manufacturing a hydrogenated cardanol-based resin according to claim 5, wherein the hydrogenation reaction in (e) above is performed in a fixed-bed reactor (FBR) filled with a catalyst.

11. A method for manufacturing a hydrogenated cardanol-based resin according to claim 10, wherein the hydrogenation reaction is performed by supplying raw materials to a fixed-bed reactor (FBR) filled with a catalyst at a flow rate of about 20 ml / min to 40 ml / min.

12. A process oil for a rubber composition for a tire tread, and The above process oil is a process oil for a tire tread comprising a hydrogenated cardanol-based resin having a weight-average molecular weight of about 800 to 1200 and a PDI of about 1.4 to 1.

8.

13. In paragraph 12, the process oil is a process oil for tire tread having a degree of aromatization of about 5% to 22%.

14. A rubber composition for a tire tread comprising a hydrogenated cardanol-based resin according to any one of claims 1 to 4.

15. In claim 14, the rubber composition for a tire tread comprises about 10 to 50 parts by weight of a hydrogenated cardanol-based resin per about 100 parts by weight of raw rubber.

16. The rubber composition for a tire tread according to claim 14, wherein the rubber composition for a tire tread has a loss factor (tanδ) of about 105 to 121 according to wet road braking force measurement (0°C) at a temperature range of about -80 to 80°C and about 10 Hz according to dynamic mechanical analysis, a loss factor (tanδ) of about 88 to 102 according to rolling resistance measurement (60°C), and a wear degree of about 113 to 116 according to a wear degree measuring instrument.

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