KR20160002277A - Phenolic Synthetic Resin and Rubber Composition for Tire Tread Comprising the Same - Google Patents

Abstract

The present invention relates to a phenolic synthetic resin and a rubber composition for a tire tread comprising the same and, more specifically, to a phenolic synthetic resin according to the present invention maintaining mechanical properties, and improving properties such a gripping power, thereby being used in manufacturing of a high performance tire.

Description

TECHNICAL FIELD [0001] The present invention relates to a phenolic synthetic resin, and a rubber composition for a tire tread comprising the same,

Phenolic synthetic resin and a rubber composition for a tire tread comprising the same.

The braking distance of the vehicle during the evaluation of the recent vehicles is becoming a major performance evaluation item and the vehicle users are also interested in the braking performance of the vehicle due to the high awareness of the safety due to frequent information about the accident of the vehicle have.

There are various requirements to be satisfied by the automobile tires, such as durability, abrasion resistance, rotational resistance, fuel economy, steering stability, ride comfort, braking performance, vibration and noise. As vehicles have become more sophisticated and safety requirements have increased, there is a need for the development of high performance tires that can maintain optimal performance on a variety of roads and climates.

Rubber constituting a tire is generally a 'viscoelastic material' having both elasticity and viscosity. As the tire rotates, it rubs against the road surface and repeats deformation and recovery periodically. At this time, the energy at the time of deformation is not completely recovered due to the viscosity of the tire, and a part of the heat energy is consumed as heat energy. This heat energy is called a hysteresis loss and a hysteresis High '. The high hysteresis means that the Tan? Value of the DMA data is large, and therefore, a method of predicting the hysteresis characteristic of the rubber composition by measuring the DMA is widely used in the tire industry.

Good grip performance means high tackiness of tire and road surface and good braking ability when cornering or stopping. From a physical point of view, the tire composition has a high hysteresis, which absorbs the strain energy received from the outside and consumes a lot of heat energy. On the other hand, as the thermal energy is consumed, the conversion rate to the driving force decreases, and the rolling resistance (R / R, rolling resistance) becomes large. As such, tires should satisfy the contradictory aspect of increasing fuel efficiency by reducing the R / R while ensuring braking by increasing the grip.

However, the external conditions in which the appearance of these properties are actually required in the tire, that is, the temperature range is different and can be overcome to a certain extent by optimizing the rubber composition for each tire region. For example, the grip force is classified into a wet grip force and a dry grip force. The grip force is a grip force on a wet road surface caused by snow or rainwater. The dry grip force refers to the grip force on a normal road surface condition.

Accordingly, in order to develop a tread rubber composition for improving the grip force, it is necessary to maintain the balance between the wet grip force and the dry grip force while minimizing the overall improvement effect and the expected R / R increase It is necessary.

There are various methods for the development of a tread rubber composition for improving grip performance. However, it can be classified into development of rubber (SBR), filler (carbon black, silica, etc.) and other additives.

Generally, when the content of carbon black or the like of the rubber composition is increased or the styrene content of the styrene-butadiene rubber (SBR) is increased, the glass transition temperature (Tg) of the composition is increased and the gripping force is improved. However, And the crack resistance is deteriorated.

Also, when silica and silica are mixed with carbon black as a filler, the effect of improving the wet grip force can be confirmed, but the wear resistance and the dry grip force are lowered. As described above, the improvement of the grip strength may cause deterioration of the required properties, so it is essential to consider the balance of physical properties, and there is a limit to the control of the rubber (SBR) and the filler.

As a technique for improving the gripping force, Korean Patent Laid-Open Publication No. 10-2011-0036495, " Rubber composition for tread and air-injected tire ", Korean Patent Laid-Open Publication No. 10-2012-0115227, " Rubber composition for tire, Korean Patent Registration No. 10-1356565 " Rubber composition for tire treads and tires made therefrom " and the like are disclosed.

Korean Patent Publication No. 10-2011-0036495 Korean Patent Publication No. 10-2012-0115227 Korean Patent Publication No. 10-1356565

The main object of the present invention is to provide a method for manufacturing a pulmonary plastic synthetic resin which can improve physical properties such as grip force while maintaining the mechanical properties of a tire as it is.

Another object of the present invention is to provide a rubber composition for a tire tread which can improve the gripping force of a tire while maintaining the mechanical properties thereof, including the phenolic synthetic resin produced by the above production method.

It is still another object of the present invention to provide a tire including the rubber made of the rubber composition for a tire tread.

In order to achieve the above object, an embodiment of the present invention provides a process for producing a phenol-based intermediate product, comprising: (P1) reacting phenols with formaldehyde in the presence of a catalyst to produce a phenolic intermediate; And a step (P2) of adding a petroleum resin to the resultant phenol-based intermediate and melting and mixing the same. The present invention also provides a method for producing a phenolic synthetic resin for use in a rubber composition for a tire tread.

In one preferred embodiment of the present invention, the catalyst may be at least one selected from the group consisting of an organic acid catalyst and an inorganic acid catalyst.

In one preferred embodiment of the present invention, the organic acid catalyst is at least one selected from the group consisting of oxalic acid and acetic acid, and the inorganic acid catalyst is selected from the group consisting of trifluoromethanesulfonic acid, fluorosulfonic acid, sulfuric acid, hydrochloric acid and nitric acid It may be more than one species.

In a preferred embodiment of the present invention, the phenol may be at least one selected from the group consisting of phenol and alkylphenol.

In one preferred embodiment of the present invention, the formaldehyde and the phenol may be added in a ratio of 1 mol: 1.05 mol to 1 mol: 1.80 mol.

In a preferred embodiment of the present invention, the step of producing the phenolic intermediate may be that the unreacted phenol content is 3% or less.

In a preferred embodiment of the present invention, the phenolic intermediate may have a weight average molecular weight of 800 to 1500 g / mol and a softening point of 90 to 150 ° C.

In a preferred embodiment of the present invention, the petroleum resin may be at least one selected from the group consisting of C5 petroleum resin, C9 petroleum resin and hydrogenated (hydrogenated) petroleum resin.

In a preferred embodiment of the present invention, the petroleum resin may have a weight average molecular weight of 800 to 1500 g / mol and a softening point of 90 to 150 ° C.

In a preferred embodiment of the present invention, the petroleum resin may be added in an amount of 20 to 80 parts by weight based on 100 parts by weight of the phenolic intermediate.

In a preferred embodiment of the present invention, the phenolic synthetic resin may have a weight average molecular weight of 750 to 2000 g / mol and a softening point of 90 to 150 ° C.

Another embodiment of the present invention provides a rubber composition for a tire tread comprising the phenolic synthetic resin produced by the above production method.

In another preferred embodiment of the present invention, the phenolic synthetic resin may have a weight average molecular weight of 750 to 2000 g / mol and a softening point of 90 to 150 ° C.

In another preferred embodiment of the present invention, the rubber composition for tire tread may comprise 3 to 30 parts by weight of phenolic synthetic resin per 100 parts by weight of rubber.

Another embodiment of the present invention provides a tire comprising a rubber comprising the rubber composition for a tire tread.

The phenolic synthetic resin according to the present invention can be effectively used for manufacturing high-performance tires by significantly improving physical properties such as grip force while maintaining the mechanical properties of the tire as it is.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

In one aspect, the present invention provides a process for producing a phenolic intermediate, comprising: (P1) reacting phenols and formaldehyde in the presence of a catalyst to produce a phenolic intermediate; And a step (P2) of adding a petroleum resin to the resulting phenol-based intermediate and melting and mixing the phenolic resin. The present invention relates to a process for producing a phenolic synthetic resin used in a rubber composition for a tire tread.

Hereinafter, the present invention will be described in detail.

First, in the process for producing a phenolic synthetic resin according to the present invention, a phenol-based intermediate is produced by reacting phenols with formaldehyde in the presence of a catalyst (P1).

According to a preferred embodiment of the present invention, the phenol may be at least one selected from the group consisting of phenol and alkylphenol. Particularly, the use of PTOP (para-tertiary octylphenol) and PTBP (para-tertiary butylphenol) It is preferable from the viewpoints of improving the compatibility of rubber and resin and reactivity with formaldehyde.

The formaldehyde and the phenol may be added in a ratio of 1 mol: 1.05 mol to 1 mol: 1.80 mol. If phenols are used in a rubber composition with a low molecular weight and a low softening point when phenol is used in an amount less than 1.05 mol based on 1 mol of formaldehyde, desired physical properties such as gripping power can not be expected and the phenol content is 1.80 mol based on 1 mol of formaldehyde The molecular weight and the softening point become unstable due to excessive reactivity, which may cause difficulty in quality control.

According to a preferred embodiment of the present invention, at least one catalyst selected from the group consisting of an organic acid catalyst and an inorganic acid catalyst may be used in the reaction between the phenol and formaldehyde. The organic acid catalyst may be at least one selected from the group consisting of oxalic acid and acetic acid. The inorganic acid catalyst may be at least one selected from the group consisting of trifluoromethanesulfonic acid, fluorosulfonic acid, sulfuric acid, hydrochloric acid and nitric acid. Among them, the use of oxalic acid is preferable in view of the reactivity between phenols and formaldehyde.

The content of the catalyst is preferably 0.5 to 1.5 parts by weight based on 100 parts by weight of the phenols. When the content of the catalyst is used within the above range, it is easy to control the reaction heat and it is possible to realize stable physical properties. If the amount is less than 0.5 part by weight, the reactivity is remarkably decreased and the desired molecular weight and softening point are difficult to obtain. If the amount is more than 1.5 parts by weight, the reaction speed increases and temperature control becomes difficult.

The reaction between the phenol and formaldehyde can be carried out at 95 ° C to 120 ° C for 4 to 8 hours, followed by deaeration at atmospheric pressure to remove moisture until bubble formation disappears to produce a phenolic intermediate. When the reaction between the phenol and formaldehyde is carried out under the above conditions, the reaction can be stably performed while controlling the reaction heat. Also, the main reaction time is preferably 4 to 8 hours so as to be designed to the desired final molecular weight.

According to a preferred embodiment of the present invention, the step of producing the phenolic intermediate satisfies that the content of the unreacted phenol is 3% or less, so that the effect of dispersing the rubber composition is excellent and the physical properties of the rubber composition such as Tan? It is effective. If the unreacted phenol content is more than 3%, unreacted volatiles are increased during the production of the rubber composition, so that desired physical properties can not be obtained and the workability is adversely affected.

The resulting phenol-based intermediate has a weight average molecular weight of 800 to 1500 g / mol, a softening point of 80 to 150 캜, and a weight average molecular weight and a softening point of the phenol-based intermediate satisfying the above range, , Tan?, And the like.

When the reaction as described above is completed, a petroleum resin is added to the resulting phenolic intermediate and then melt-mixed (P2). In this case, in the step P2, the catalyst added in the step P1 is used without being neutralized or recovered, thereby shortening the reaction time and reducing the generation of by-products.

According to a preferred embodiment of the present invention, the petroleum resin added to the phenolic intermediate may be at least one selected from the group consisting of C5 petroleum resin, C9 petroleum resin and hydrogenated (hydrogenated) petroleum resin, The use of an addition (hydrogenated) petroleum resin is preferable from the viewpoint of improving Tan 隆 of the rubber composition in a specific temperature range.

The petroleum resin preferably has a weight average molecular weight of 800 to 1500 g / mol and a softening point of 90 to 150 ° C in view of compatibility with the intermediate and the range of the molecular weight and softening point of the final resin.

The petroleum resin may be added in an amount of 20 to 80 parts by weight based on 100 parts by weight of the phenol-based intermediate produced in the step P1. If the amount is less than 20 parts by weight or more than 80 parts by weight based on 100 parts by weight of the phenol-based intermediate, the effect of improving the gripping force of the rubber composition may be reduced by half.

When the petroleum resin is added to the phenol-based intermediate and the mixture is melt-mixed, the reaction may be carried out at 160 to 170 ° C for 1 to 2 hours. When the petroleum resin is added to the phenol-based intermediate and the melt-mixing is carried out under the above-mentioned conditions, the mixing time can be shortened while maintaining the efficiency of melt-mixing and the final molecular weight can be easily realized.

Upon completion of the reaction, the phenolic resin is obtained by vacuum degassing to remove unreacted monomers, thereby satisfying the final desired weight average molecular weight and softening point.

The phenol-based synthetic resin produced in this way has a weight average molecular weight of 750 to 2000 g / mol and a softening point of 90 to 150 ° C. The weight average molecular weight and the softening point of the phenol resin satisfy the above ranges, , Tan?, And the like.

In another aspect, the present invention relates to a rubber composition for a tire tread comprising the phenolic synthetic resin produced by the above production method.

When the phenolic synthetic resin prepared as described above is used in a rubber composition for a tire tread, it is possible to obtain an effect of improving the grip by increasing the hysteresis of the rubber composition.

Specifically, the rubber composition for a tire tread is used for a rubber for manufacturing a tire tread. Since the tread touches the road surface in the structure of the tire, it is important to improve the grip force more than anything. The tire (rubber composition) undergoes repeated deformation and recovery, in which a part of the input energy is converted into heat. This energy loss per strain is called hysteresis. The phenolic synthetic resin produced by the above-mentioned production method increases the hysteresis of the rubber composition for tire tread, and absorbs a large amount of external energy into heat energy during tire braking. This effect improves the gripping force.

Particularly, the phenolic synthetic resin has a weight average molecular weight of 750 to 2000 g / mol and a softening point of 90 to 150 캜, which contains a rubber composition for a tire tread to increase the hysteresis at room temperature, Can be improved.

The rubber composition for tire tread may comprise 3 to 30 parts by weight of phenolic synthetic resin based on 100 parts by weight of rubber. In this case, when the phenolic synthetic resin is contained in an amount less than 3 parts by weight based on 100 parts by weight of the rubber, it is difficult to expect a visible gripping effect. If the amount exceeds 30 parts by weight, dispersion efficiency is low and uniform physical properties are difficult to realize.

The rubber may be at least one selected from the group consisting of styrene-butadiene rubber, styrene-butadiene rubber, styrene rubber and butadiene rubber.

The rubber composition for a tire tread may further comprise other compounding agents added to a rubber composition for a tire tread, such as carbon black and silica as a reinforcing agent; N-tert-butylbenzothiazole-2-sulfenamide (TBBS), Ntert-butyl-2-benzoylsulfenamide, CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) and the like as a crosslinking accelerator; Bis [3- (triethoxysilyl)] tetrasulfide as the silane coupling agent, 6, Dipropylene glycol as the activator, sulfur such as crosslinking agent, stearic acid, zinc oxide and the like; As the antioxidant, N-1,3-dimethylbutylpoly 2,2,4-trimethyl, 1,2-dihydroquinoline, waxy hydrocarbon and the like can be used.

According to another embodiment of the present invention, there is provided a tire comprising a rubber made of the above-mentioned rubber composition.

The tire can be manufactured by using the rubber composition described above and adopting a method of manufacturing a tire commonly known in the field to which the present invention belongs.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described. However, the following embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to the following embodiments.

≪ Preparation Example 1 > Preparation of phenolic synthetic resin

2,500 g of PTBP (para-tertiarybutylphenol) (SI Group) and 1,013 g of 37% formaldehyde (Alpha Chemika) were added to a glass reactor equipped with a stirrer, a condenser and a nitrogen inlet and dissolved at 80 ° C., 15 g of oxalic acid (Daemyung Chemical) was added and the reflux reaction was carried out for 4 hours while stirring. After the reflux reaction was completed, water was removed until the bubbles disappeared by normal pressure degassing to 160 ° C to obtain a phenol-based intermediate.

Next, 30 parts by weight of a hydrogenated (hydrogenated) petroleum resin (KOLON INDUSTRIES, SU-120) having a weight average molecular weight of 850 g / mol on a Mw basis and a softening point of 120 ° C was added to the phenol- Deg.] C to 180 [deg.] C to remove unreacted monomers, and then a phenolic synthetic resin having a softening point of 117 [deg.] C was prepared.

≪ Preparation Example 2 > Preparation of phenolic synthetic resin

Except that 10 parts by weight of a petroleum resin was added to the phenol-based intermediate.

≪ Preparation Example 3 > Preparation of phenolic synthetic resin

Was prepared in the same manner as in Production Example 1, except that 50 parts by weight of a petroleum resin was added to the phenol-based intermediate.

≪ Preparation Example 4 > Preparation of phenolic synthetic resin

Was prepared in the same manner as in Preparation Example 1, except that 70 parts by weight of the petroleum resin was added to the phenol-based intermediate.

≪ Preparation Example 5 > Preparation of phenolic synthetic resin

Was prepared in the same manner as in Preparation Example 1, except that 90 parts by weight of petroleum resin was added to the phenol-based intermediate.

The phenolic synthetic resins produced according to Production Examples 1 to 5 were measured for their physical properties by the following methods, and the results are shown in Table 1 below.

(1) Measurement of softening point

The measurement was carried out at a rate of 5 DEG C / min using a FT900 and 83HT manufactured by Mettler Toledo Co.

(2) Molecular weight measurement

The phenolic synthetic resins prepared according to Preparation Examples 1 to 5 were dissolved in Tetra Hydro Furan (THF) at a concentration of 4000 ppm and the weight average molecular weight (Mw) was measured using Gel Permeation Chromatography (GPC) And number average molecular weight (Mn) were measured.

(3) Molecular weight dispersion (PDI) measurement

(Mw) and number-average molecular weight (Mn) measured in (2) Weight average molecular weight ratio.

division Production Example 1 Production Example 2 Production Example 3 Production Example 4 Production Example 5 Phenolic
Synthetic resin
Properties Softening point (℃) 117.0 116.0 118.5 118.6 119.0 Number average molecular weight (Mn) 576 g / mol 575 / mol 576 g / mol 580mol 588mol Weight average molecular weight (Mw) 829 g / mol 823 g / mol 835 g / mol 841 g / mol 847 g / mol Molecular weight dispersion (PDI) 1.44 1.43 1.45 1.45 1.44

Example 1 Production of Rubber Specimen

55 parts by weight of silica, 10 parts by weight of carbon black, 6 parts by weight of bis [3- (triethoxysilyl)] tetrasulfide, 3 parts by weight of zinc oxide, 1 part by weight of stearic acid 1 1.5 parts by weight of dipropylene glycol, 2 parts by weight of sulfur and 1.5 parts by weight of CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) and 5 parts by weight of the phenolic synthetic resin prepared in Preparation Example 1 were added to the mixture, And then vulcanized at 160 DEG C for 20 minutes to prepare a test rubber specimen.

Example 2 Preparation of Rubber Specimen

The procedure of Example 1 was repeated except that phenolic synthetic resin prepared in Production Example 2 was used instead of phenolic synthetic resin.

Example 3 Preparation of Rubber Specimen

The procedure of Example 1 was repeated except that phenolic synthetic resin prepared in Production Example 3 was used instead of phenolic synthetic resin.

Example 4 Preparation of Rubber Specimen

The procedure of Example 1 was repeated except that phenolic synthetic resin prepared in Production Example 4 was used instead of phenolic synthetic resin.

Example 5 Production of Rubber Specimen

The procedure of Example 1 was repeated except that phenolic synthetic resin prepared in Production Example 5 was used instead of phenolic synthetic resin.

Example 6 Production of Rubber Specimen

The procedure of Example 1 was repeated except that 10 parts by weight of the phenolic synthetic resin prepared in Production Example 1 was used as the resin.

Example 7 Preparation of Rubber Specimens

The procedure of Example 1 was repeated except that 10 parts by weight of the phenolic synthetic resin prepared in Production Example 3 was used as the resin.

<Example 8> Preparation of rubber specimen

The procedure of Example 1 was repeated except that 10 parts by weight of the phenolic synthetic resin prepared in Production Example 4 was used as the resin.

&Lt; Comparative Example 1 >

Except that 5 parts by weight of a phenol resin (KPH-F2002, KOLON INDUSTRIS) (softening point: 100 占 폚, weight average molecular weight: 1746 g / mol) was used instead of the phenolic synthetic resin prepared in Production Example 1 The same procedure was followed.

&Lt; Comparative Example 2 >

Except that 5 parts by weight of an alkylphenol resin (KPT-S1503, KOLON INDUSTRIS) (softening point: 95 占 폚, weight average molecular weight: 1724 g / mol) was used instead of the phenolic synthetic resin prepared in Production Example 1 . &Lt; / RTI &gt;

&Lt; Comparative Example 3 >

Except that 5 parts by weight of an alkylphenol resin (KPA-1350K, KOLON INDUSTRIS) (softening point: 112 占 폚, weight average molecular weight: 1245 g / mol) was used instead of the phenolic synthetic resin prepared in Production Example 1 . &Lt; / RTI &gt;

&Lt; Comparative Example 4 >

Except that 5 parts by weight of an alkylphenol resin (KPA-F1360, KOLON INDUSTRIS) (softening point: 139 占 폚, weight average molecular weight: 1790 g / mol) was used instead of the phenolic synthetic resin prepared in Production Example 1 . &Lt; / RTI &gt;

&Lt; Comparative Example 5 >

Except that 5 parts by weight of a petroleum resin (A-1100, KOLON INDUSTRIS) (softening point: 100 占 폚, weight average molecular weight: 1736 g / mol) was used instead of the phenolic synthetic resin prepared in Production Example 1 The same procedure was followed.

&Lt; Comparative Example 6 >

Except that 5 parts by weight of a petroleum resin (P-90, KOLON INDUSTRIS) (softening point: 95 캜, weight average molecular weight: 942 g / mol) was used instead of the phenolic synthetic resin prepared in Production Example 1 The same procedure was followed.

The rubber specimens prepared according to Examples 1 to 6 and Comparative Examples 1 to 6 were measured for physical properties by the following methods, and the results are shown in Table 2 below.

(1) Tensile strength measurement

The tensile stress-strain characteristics include tensile strength, elongation and tensile stress. ISO 37, ASTM D412, BS 903: Part A2, DIN 53504 specify the standard method for determining these properties. Test specimens have dumbbells type 1 ~ 4, mainly 3. (Low elongation at 1 arc, low tensile strength at 2 arc, pure rubber formulation and latex product 4 arc). The thickness is 2 ~ 3mm. Tensile properties refer to tensile strength, elongation, tensile stress, and the like. These properties are measured by pulling a standard specimen at a constant speed in a device called a tensile tester.

Tensile strength is expressed in MPa, N / mm ² , kg / cm ² , and lb / cm ² as the force or stress to be cut when a standard specimen is pulled at a constant speed. Each tensile strength of the rubbers are shown differently from below 7MPa (71kg / cm ²⁾ according to the used raw material rubber and compounding agents to more than 45MPa (451kg / cm ^2).

The definition of elongation or deformation is expressed as a percentage of the initial length as an increased length indicated by the tensile force applied to the standard specimen. For example, a 300% elongation rate means that the specimen is four times the initial length. Ultimate elongation (Elongation at break) indicates the elongation at break, which is obtained automatically at the tensile strength test. Cutting elongation varies from 100% to 1000% depending on the rubber compound, which usually means elongation or elongation in rubber tests.

Tensile modulus (tensile modulus) applied to rubber is defined as the force required to maintain a constant elongation, expressed in MPa, N / mm ² , kg / cm ² , and lb / cm ² , equal to the tensile strength. Typically measured tensile stress (modulus) is at 100% and 300% elongation, say 100% tensile stress is 5 MPa if the force required to maintain 100% elongation is 5 MPa (51 kgf / cm ² ). Tensile stresses represent the degree of hardness and vulcanization of rubber compounds, usually obtained during testing of tensile strength. The 100% tensile stress of other rubber compounds varies from less than 1 MPa (13.2 kg · f / cm ² ) to more than 13 MPa (133 kg · f / cm ² ) depending on the chemical composition of the rubber compound.

The test temperature has a large effect on the results. Therefore, the temperature should be adjusted and recorded in the measurement report. The standard laboratory temperature specified in ISO 37 is [20 (± 2) ° C, 23 (± 2) ° C, 27 (± 2) ° C]. The change in elongation rate has a great effect on tensile stress and elongation. As the elongation rate increases, the tensile stress increases, the elongation decreases, and the tensile strength increases or decreases.

Tensile testing is useful for product management. In particular, the tensile strength is susceptible to any change in the rubber compound caused by manufacturing errors. Tensile testing is useful for measuring the resistance of rubber to aging caused by heat, liquids, gases, chemicals, ozone, and weather. For this purpose, tensile strength, tensile stress, and elongation are measured before and after the exposure test. If the change of these values is small, the service life is expected to be long.

- Device Specifications and Conditions

Model: U.T.M - Shimadzu AG-1S (Load cell: PFG-5kN)

Specimen specification: Dumbbell No. 3

Test speed: 500 mm / min

Measured data: Load value (kgf), tensile force (kgf), elongation (%), modulus (kgf, 50%, 100%, 300%

- Test Procedure

① Sample Preparation

Relaxation of the rubber sheet which is bridged by press work for more than 24 hours and cut according to the standard of dumbbell No. 3. It is important to note that when cutting a sheet with a certain thickness through an open-roll operation, the direction must be marked and cut in a certain direction to reduce the deviation. The thickness of each cut specimen is measured using a back gauge.

② Set the program

Set the test type (for tensile measurement), test conditions (test speed, physical property to be calculated), and calibrate the elongation and load values. Calibrations are required for each measurement in the case of a stretcher.

The elongation is necessary for the elongation measurement of flexible materials such as rubber, and if the load cell specification and the program set value do not match, the reliability of the data may deteriorate.

③ Specimen attachment and data processing

After inputting the thickness values of each specimen measured with a posterior instrument, insert the specimen into the grip of the U.TM instrument. At this time, considering the position of the extensor, position the extensor so that it can fit the measuring range of the specimen.

In case of tensile force and modulus except for Load value and elongation, the thickness of specimen is reflected. Therefore, pay attention to thickness measurement. If the fracture surface exceeds the measurement value after completion of test, mark it. do.

(2) Hardness measurement

The hardness of the rubber is defined as the extent to which the surface will resist indentor penetration of a defined size under a specified load. The durometer is divided into several types according to the pressing and load method at the same time as the test. It has a constant scale value that can read the value, and the scale is randomly divided from 0 (very flexible) to 100 (rigid), and the load is applied in dead load and spring form.

Hardness is expressed as IRHD (International Rubber Hardness Degrees) or Shore hardness (Shore hardness degrees). The IRHD test is based on the principle of measuring the degree of penetration of a specified ball of rigidity into a specimen under a constant specified static load. The Shohe durometer, called Durometer, has type A and type D. The calibrated spring pushes the specified pressure needle onto the specimen. Type A durometer has a blunt cone bell and is used to measure flexible rubber hardness up to about 90 Shore A. A D-type hardness meter with an A-type hardness gauge and other springs and a pointed cone bell is used to measure the hardness of hard materials above 90 Shore A.

The Shore unit is almost the same as the IRHD unit, but there should be no direct conversion because there can be big differences. Most rubber products vary in hardness from 40 to 90 IRHD for practical use. A hardness of 40 or less can be obtained by adding a large amount of a plasticizer when mixing the rubber.

For thinner specimens, a micro IRHD instrument (a miniature standard test) is used. The thickness of the micro test standard specimen is 2.0 (± 0.2) mm. Thicknesses in this range are often consistent with results from standard tests using standard specimens. Thicker or thicker specimens may be used, but in any case they should be at least 1 mm thick. In the end, the minimum distance from the edge of each thickness is given in ISO 48, 1400, 1818. The hardness test is based on standard laboratory temperature [20 (± 2) The test report shall contain the following information: (a) the dimensions of the specimen, (b) the temperature, (c) the type of surface to be measured (forming, Buff), etc.), (d) The type of test equipment used shall be recorded.

All tests performed on non-standard specimens are called apparent hardness. Standard hardness refers to the test carried out on a standard specimen (8 to 10 mm for the standard test and 2.0 (μ 0.2) mm for the micro test). Elastic products made from the same material can have different apparent hardnesses depending on their shape and thickness. Test results (eg O-rings) obtained from curved surfaces are merely arbitrary values that can be applied to a specific part and may show a difference of 10 or more in IRHD.

- Measuring equipment

Model: Shore Hardness Tester (Shore-A type)

Specimen Specification: Vulcanized rubber Sheet Thickness 7mm ± 0.5mm

- Test Procedure

① Sample Preparation

The specimen is subjected to press work to relax the crosslinked rubber sheet for more than 24 hours, and then to normalize the thickness by three layers. The hardness is affected by the thickness of the specimen and should be at least 4mm and 8mm ~ 10mm is recommended.

② Measurement of physical properties

The crosslinked rubber sheet is measured five times for each site to obtain an average value. The edge of the cross-linked rubber sheet should be avoided because there may be an edge effect when measuring the physical properties.

(3) Measurement of abrasion

The abrasion resistance is defined as the abrasion resistance of a moving rubber compound by contact with a wear surface. Wear is a very important characteristic to consider when rubber products are used in dynamic conditions. Dynamic seals, for example, are subject to wear when moving on relatively dry and highly friction surfaces.

The coefficient of friction of a rubber is influenced by a number of factors such as the shape and composition of the rubber part and the relative material, temperature, pressure, friction speed, surface roughness and the like. Severe friction can be very bad because it generates heat which causes rubber deterioration. Such friction may be considerably reduced by appropriate lubricant or chemical treatment of the surface. Lubricant-containing rubber compounds may also be used, if at least friction is required or the lubricant is still not certain. Test methods are described in ISO 4649, ASTM D 2228 and D 1630, BS 903: Part A9, DIN 553516. All of these tests fix the specimen of the rubber compound against the wear surface under the specified load and speed. The volume loss of the rubber specimen is measured and the result is expressed as a percentage compared to standard rubber.

(4) Dynamic Mechanical Analysis (DMA) measurement

Dynamic Mechanical Analysis measures the mechanical analysis of a material as a function of temperature, frequency, and vibration. When periodic external force is applied to the specimen, cyclic stress is generated in the specimen, and the specimen reacts to this stress, resulting in a corresponding deformation. The mechanical modulus is determined from the stress and deformation at this time. Shear modulus (G) and Young's modulus (E) are measured according to the applied stress type. That is, a phase difference is generated according to a periodically varying stress (sinusoidal stress) due to a time delay due to the viscoelastic property of the material. The modulus measured dynamically in consideration of this phase difference is described by G '(storage modulus) and G''(loss modulus). G 'is a direct result of the DMA measurement, which is the in-phase response of the sample with periodic stress and corresponds to the reversible elasticity of the sample. The hypothetical component G '' is a phase-shifted response up to 90 ^O and corresponds to the mechanical energy that is irreversibly lost to heat. The tan δ of this phase difference is a loss factor and is used to measure the damping behavior of the material. For rubber, the higher the tanδ @ 0 ℃, tanδ @ 25 ℃ and tanδ @ 70 ℃, the better the wet grip and dry grip, and the rolling resistance decreases.

- Device Specifications and Conditions

Model: TA-DMA Q800

Test Mode: Multi-Frequency-Strain

Clamp Type: Tension-Film

Frequency: 11Hz

Preload force: 0.01 N

Poisson's ratio: 0.44

Measuring range: -50 占 폚 (holding for 5 minutes) to 75 占 폚, heating rate: 3 占 min

- Test Procedure

① Sample Preparation

- The specimen is cut by crossing the rubber sheet crossed by press work for more than 24 hours and then cut to 10 ± 0.2 (W, measured value) × 12 ~ 13 (L, automatic measurement) × 2 ~ 2.5mm Then enter the correct number.

- Basically, when cutting the specimen, the cut surface should be clean so that there is no significant difference in the specimen dimensions. When writing the dimension value, it is recommended to measure the dimension at various angles to input the correct value.

② Calibration

-Calibration is basically divided into Position, Mass, and Compliance Calibration. In the state where Clamp is removed, Position, Load the selected clamp, Load the standard specimen, and finally calibrate Compliance.

-Calibration is basically performed when the instrument is first turned on, when liquid nitrogen is recharged, when the test is changed by replacing the clamp.

③ Attaching the specimen

- Use the specified tool (small wrench) to attach the specimen to the clamp. The inside of the chamber is composed of various sensitive devices for driving the temperature sensor clamp, so be careful not to apply excessive force when using it.

④ Data Processing

- All data is processed automatically. After saving the file, G ', G' 'and Tan δ are obtained by the program according to the temperature change. The Tg value of the rubber compound can be determined from the maximum point of the tanδ peak.

division Example Comparative Example One 2 3 4 5 6 7 8 One 2 3 4 5 6 Mechanical properties Breaking Tensile Strength (kgf) 208.82 205.32 207.89 206.84 202.21 205.57 205.70 208.01 204.55 204.59 205.66 203.12 202.71 202.85 Elongation at break (%) 310.99 307.10 308.29 312.50 310.53 306.71 308.52 307.21 310.28 310.12 311.52 308.56 309.33 309.45 Modulus at 50% elongation (kgf) 30.96 31.55 31.16 30.30 30.12 29.90 30.08 30.30 30.85 30.86 31.05 30.25 30.19 30.22 Modulus at 100% elongation (kgf) 59.48 59.32 59.15 57.96 57.25 56.11 60.77 62.50 57.84 57.85 58.12 57.12 57.01 57.85 Modulus at 300% elongation (kgf) 201.40 202.63 199.23 194.39 190.74 191.61 199.49 195.06 192.56 192.60 193.45 190.98 190.60 191.28 Hardness
(Shorea) 80 79 80 80 79 79 79 79 79 79 80 79 79 79 DIN Abrasion
(Loss weight) 0.358 0.395 0.355 0.351 0.388 0.370 0.383 0.382 0.395 0.385 0.378 0.387 0.389 0.381 DMA Tanδ
(0 C) 0.2505 0.2432 0.2636 0.2517 0.2421 0.2510 0.2644 0.2524 0.2427 0.2407 0.2386 0.2412 0.2417 0.2424 Tanδ
(25 DEG C) 0.1952 0.1844 0.1983 0.1964 0.1582 0.1956 0.2089 0.2069 0.1862 0.1842 0.1821 0.1823 0.1543 0.1550 Tanδ
(70 ° C) 0.1892 0.1948 0.2023 0.1904 0.1433 0.1906 0.2040 0.1920 0.1961 0.1941 0.1920 0.1923 0.1431 0.1437 Tg (占 폚) -22.55 -22.98 -22.73 -22.12 -23.02 -21.15 -21.33 -21.02 -24.38 -24.52 -24.33 -24.26 -25.45 -25.89

As shown in the above Table 2, Examples 1 to 8 show the values of Tan δ (0 ° C.) and Tan δ (25 ° C.) values, which are comparable to or higher than those of Comparative Examples 1 to 6 in mechanical properties and abrasion Was higher than those of Comparative Examples 1 to 6 and the glass transition temperature (Tg) was also higher. As a result, the wet grip force and the dry grip force of the tire can be expected to be improved.

In addition, Tand? (70 占 폚) values of Examples 1 to 8 are similar to those of Comparative Examples 1 to 4, and it is expected that the properties of such a rubber composition improve the grip feeling of the tire without greatly deteriorating the rolling resistance characteristics.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (15)

Reacting phenols and formaldehyde in the presence of a catalyst to produce a phenolic intermediate (P1); And a step (P2) of adding a petroleum resin to the resulting phenolic intermediate and melt-mixing the resulting mixture.
The process for producing phenolic synthetic resin according to claim 1, wherein the catalyst is at least one selected from the group consisting of an organic acid catalyst and an inorganic acid catalyst.
3. The catalyst according to claim 2, wherein the organic acid catalyst is at least one member selected from the group consisting of oxalic acid and acetic acid, and the inorganic acid catalyst is at least one member selected from the group consisting of trifluoromethanesulfonic acid, fluorosulfonic acid, sulfuric acid, Wherein the phenolic resin is a polyphenol resin.
The process for producing phenolic synthetic resin according to claim 1, wherein the phenol is at least one selected from the group consisting of phenol and alkylphenol.
The method according to claim 1, wherein the formaldehyde and the phenol are added in a ratio of 1 mol: 1.05 mol to 1 mol: 1.80 mol.
The process for producing a phenolic synthetic resin according to claim 1, wherein the step of producing the phenolic intermediate is an unreacted phenol content of 3% or less.
The process for producing a phenolic synthetic resin according to claim 1, wherein the phenolic intermediate has a weight average molecular weight of 800 to 1500 g / mol and a softening point of 90 to 150 ° C.
The method for producing phenolic synthetic resin according to claim 1, wherein the petroleum resin is at least one selected from the group consisting of C5 petroleum resin, C9 petroleum resin and hydrogenated (hydrogenated) petroleum resin.
The process according to claim 1, wherein the petroleum resin has a weight average molecular weight of 800 to 1500 g / mol and a softening point of 90 to 150 ° C.
The method for producing phenolic synthetic resin according to claim 1, wherein the petroleum resin is added in an amount of 20 to 80 parts by weight based on 100 parts by weight of the phenol-based intermediate.
The method according to claim 1, wherein the phenolic synthetic resin has a weight average molecular weight of 750 to 2000 g / mol and a softening point of 90 to 150 ° C.
A rubber composition for a tire tread comprising the phenolic synthetic resin produced by the method of any one of claims 1 to 11.
The rubber composition for a tire tread according to claim 12, wherein the phenolic synthetic resin has a weight average molecular weight of 750 to 2000 g / mol and a softening point of 90 to 150 캜.
The rubber composition for tire tread according to claim 12, wherein the rubber composition for tire tread comprises 3 to 30 parts by weight of phenolic synthetic resin based on 100 parts by weight of rubber.
A tire comprising the rubber of claim 12.