Diene compound modified alkyl phenolic resin and application thereof as tackifying resin

Abstract

The invention provides alkyl phenolic resin capable of being used as tackifying resin. The alkyl phenolic resin is prepared by reacting an alkylphenol compound, a diene compound and an aldehyde compound. The main chain of the alkyl phenolic resin is modified, and flexible long hydrocarbon chains, ether bonds and the like are introduced, so that the rigidity of the tackifying resin is reduced, the compatibility of the resin and rubber is improved, and the compression fatigue heat generation of vulcanized rubber is reduced.

Description

Technical Field

[0001] The invention belongs to the field of phenolic resins, and relates to diene compound modified alkyl phenolic resin and application thereof as tackifying resin. Background Art

[0002] In the process of tire manufacturing, in order to make the uncured film fit tightly and prevent the semi-finished product from being deformed and bubbles from being generated due to film displacement, tackifying resin is used as a tire processing aid to improve the surface viscosity of the uncured film. A variety of resins including C5 resin, C9 resin, terpene resin, coumarone-indene resin, and phenolic resin can be used as tackifying resins. Common tackifying resins in the market include tert-butylphenol-formaldehyde resin, tert-octylphenol-formaldehyde resin, tert-butylphenol-acetylene resin, etc. Among them, alkylphenol-formaldehyde resin is artificially synthesized and has the characteristics of strong structural controllability. It is currently the most widely used tackifying resin in the tire industry. The currently generally recognized viscosity-increasing mechanism of alkylphenol-formaldehyde resin is that the alkylphenol-formaldehyde resin migrates to the surface of the film and forms a cross-linked network through the hydrogen bonds of the phenolic hydroxyl groups in the interface layer of the film, so that the two films fit firmly together; the alkyl group on the side chain of the alkylphenol-formaldehyde resin provides a certain compatibility between the alkylphenol-formaldehyde resin and the rubber, so that the resin can continuously migrate from the inside of the rubber to the surface, providing a long-lasting viscosity-increasing effect.

[0003] Tires can be regarded as rubber materials with complex structures, showing typical viscoelasticity, that is, under periodic forces, strain lags behind stress. It is precisely because of the viscoelasticity of rubber that the material generates dynamic heat. On the one hand, dynamic heat generation participates in the formation of rolling resistance, which increases the energy consumption during the operation of the finished tire. On the other hand, dynamic heat generation accelerates the aging of rubber, which reduces the service life of the tire. Usually, alkylphenol-formaldehyde resin does not participate in the vulcanization process of rubber, but only plays a role in the tire processing process. After the rubber is vulcanized, it remains inside the vulcanized rubber. The hydrogen bonds of alkylphenol-formaldehyde resin still exist. In the process of rubber deformation, hydrogen bonds convert part of the kinetic energy into heat energy, which aggravates the dynamic heat generation of the tire. The main chain of alkylphenol-formaldehyde resin contains a large number of rigid benzene ring structures, which also makes the friction heat generation between the polymer segments inside the rubber serious.

[0004] Some novel tackifying resins have improved dynamic properties. CN102924672B uses halogenated compounds to convert part of the phenol structure into ether bonds, and achieves the effect of improving the dynamic properties of rubber by reducing the phenolic hydroxyl group, but the tackifying effect of alkylphenolic resin is mainly achieved by the phenolic hydroxyl group, and reducing the phenolic hydroxyl group will weaken the tackifying effect. CN106967204B uses a phenolic compound containing a carbon-carbon double bond and an alkylphenol co-condensation reaction, and introduces the double bond into the side chain of the tackifying resin, so that part of the resin participates in the crosslinking of the rubber, and the movement of the phenolic resin inside the vulcanized rubber is limited, thereby achieving the effect of reducing dynamic heat generation, but the main chain of the alkylphenolic resin still contains a large amount of rigid benzene ring structure, which is not conducive to reducing friction heat generation. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a diene compound modified alkylphenol-formaldehyde resin that can be used as a tackifying resin. The present invention modifies the main chain of the alkylphenol-formaldehyde resin, introduces a flexible long hydrocarbon chain, an ether bond, etc., reduces the rigidity of the tackifying resin, increases the compatibility of the resin with rubber, and reduces the compression fatigue heat generation of the vulcanized rubber. Preferably, the present invention introduces heteroatoms such as oxygen into the main chain of the tackifying resin to enhance the hydrogen bonds between the phenolic resins to improve the tackifying effect, and obtains special properties brought by other heteroatoms.

[0006] Specifically, the present invention provides an alkylphenol-formaldehyde resin, which is prepared by reacting an alkylphenol compound, a diene compound and an aldehyde compound;

[0007] The alkylphenol compound is a compound of formula I:

[0008]

[0009] In formula I, R1 is selected from C1-C20 alkyl;

[0010] The diene compound is selected from the group consisting of a compound of formula IIA, a compound of formula IIB and a compound of formula IIC:

[0011]

[0012] In Formula IIA, R2 and R5 are each independently selected from H and C1-C4 alkyl, R3 and R4 are each independently selected from C1-C10 alkylene, a, b, c, d, e, f and g are each independently 0 or 1, c and e are not 0 at the same time, c is not 0 when b and d are both 1, and e is not 0 when d and f are both 1; In Formula IIB, R6 and R7 are each independently selected from H and C1-C4 alkyl, R8 and R9 are each independently selected from C1-C10 alkylene; In Formula IIC, R 10 and R 11 Each is independently selected from C1-C10 alkylene.

[0013] In one or more embodiments, in Formula I, R1 is selected from C1-C10 alkyl; preferably, R1 is selected from tert-butyl and tert-octyl.

[0014] In one or more embodiments, in Formula IIA, R2 and R5 are each independently selected from H and methyl, and R3 and R4 are each independently selected from C1-C4 alkylene.

[0015] In one or more embodiments, in Formula IIB, R6 and R7 are each independently selected from H and methyl, and R8 and R9 are each independently selected from C1-C4 alkylene.

[0016] In one or more embodiments, in Formula IIC, R 10 and R 11 Each is independently selected from C1-C4 alkylene.

[0017] In one or more embodiments, the diene compound is selected from one or more of 1,5-hexadiene, diethylene glycol divinyl ether, diallyl ether, dipropylene glycol diacrylate, 1,4-butanediol dimethacrylate, diallyl dimethyl silane and diallyl sulfide, preferably selected from one or more of diethylene glycol divinyl ether, dipropylene glycol diacrylate, diallyl dimethyl silane and diallyl sulfide.

[0018] In one or more embodiments, the aldehyde compound is selected from one or more of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, benzaldehyde and furfural, preferably formaldehyde.

[0019] In one or more embodiments, the amount ratio of the alkylphenol compound to the diene compound is 1:(0.03-0.06), preferably 1:(0.04-0.05).

[0020] In one or more embodiments, the molar ratio of the alkylphenol compound to the aldehyde compound is 1:(0.6-0.9), preferably 1:(0.7-0.8).

[0021] In one or more embodiments, the alkylphenol-formaldehyde resin is formed by reacting an alkylphenol compound, a diene compound and an aldehyde compound in a molar ratio of 1: (0.03-0.06): (0.6-0.9); preferably, the alkylphenol-formaldehyde resin is formed by reacting an alkylphenol compound, a diene compound and an aldehyde compound in a molar ratio of 1: (0.04-0.05): (0.7-0.8).

[0022] In one or more embodiments, the alkylphenol-formaldehyde resin has a softening point of 90 to 145°C.

[0023] In one or more embodiments, the alkylphenol-formaldehyde resin has a free alkylphenol compound content of ≤ 5.1%.

[0024] The present invention also provides a method for preparing the alkylphenol-formaldehyde resin described in any embodiment of the present invention, the method comprising the following steps:

[0025] (1) subjecting the alkylphenol compound to a Friedel-Crafts reaction with the diene compound so that the double bonds of the diene compound are completely consumed to obtain a prepolymer;

[0026] (2) subjecting the alkylphenol compound, the aldehyde compound and the prepolymer obtained in step (1) to a condensation polymerization reaction to obtain the alkylphenol-formaldehyde resin.

[0027] In one or more embodiments, one molecule of the prepolymer is formed by the reaction of at least one molecule of the diene compound and at least two molecules of the alkylphenol compound; preferably, one molecule of the prepolymer is formed by the reaction of one molecule of the diene compound and two molecules of the alkylphenol compound.

[0028] In one or more embodiments, the reaction of step (1) and step (2) is carried out in the presence of an acidic catalyst.

[0029] In one or more embodiments, the acid catalyst is selected from one or more of p-toluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, benzene disulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, sulfuric acid and phosphoric acid, preferably p-toluenesulfonic acid.

[0030] In one or more embodiments, the acid catalyst is used in an amount of 0.2 mol% to 1 mol% of the phenolic compound.

[0031] In one or more embodiments, the reaction temperature of step (1) is 80 to 140° C., and the reaction time is 10 to 200 minutes.

[0032] In one or more embodiments, the reaction temperature of step (2) is 90 to 180° C., and the reaction time is 10 min to 12 h;

[0033] In one or more embodiments, in step (1), the molar ratio of the alkylphenol compound to the diene compound is greater than 2:1, and unreacted alkylphenol compound and the prepolymer are present in the obtained reaction system; in step (2), the alkylphenol compound is optionally added to the reaction system obtained in step (1), and then the aldehyde compound is slowly added to carry out a condensation reaction.

[0034] In one or more embodiments, after the reaction of step (2) is completed, a quenching agent is added to quench the reaction, and water and free alkylphenol compounds are removed by distillation under reduced pressure.

[0035] In one or more embodiments, the quencher is selected from one or more of an inorganic base and an organic base, preferably triethanolamine.

[0036] The present invention also provides an alkylphenol-formaldehyde resin prepared by the method described in any embodiment of the present invention.

[0037] The present invention also provides a rubber composition, which contains a diene elastomer and an alkylphenol-formaldehyde resin as described in any embodiment of the text as a tackifying resin; preferably, the mass ratio of the diene elastomer to the alkylphenol-formaldehyde resin is 100:(1-5).

[0038] The present invention also provides use of the alkylphenol-formaldehyde resin described in any embodiment herein for increasing the surface adhesion of rubber and / or reducing the compression fatigue heat generation of rubber. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0040] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0041] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0042] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions).

[0043] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0044] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0045] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0046] The present invention first utilizes the Friedel-Crafts reaction between the double bond of the diene compound and the alkylphenol compound to obtain a condensate of the diene compound and the alkylphenol compound (referred to herein as a prepolymer), wherein one molecule of the prepolymer is formed by the reaction of at least one molecule of the diene compound and at least two molecules of the alkylphenol compound; and then the prepolymer is subjected to a polycondensation reaction with the alkylphenol compound and an aldehyde compound to obtain a diene compound-modified alkylphenol-formaldehyde resin (also referred to as the alkylphenol-formaldehyde resin of the present invention). In some embodiments, one molecule of the prepolymer is formed by the reaction of one molecule of the diene compound and two molecules of the alkylphenol compound. The alkylphenol-formaldehyde resin of the present invention can be used as a tackifying resin for rubber, has good compatibility with rubber, and can reduce compression fatigue heat generation of vulcanized rubber.

[0047] The alkylphenol compound suitable for use in the present invention may have a structure shown in Formula I:

[0048]

[0049] In formula I, R1 is selected from C1-C20 alkyl.

[0050] In some embodiments, in Formula I, R1 is selected from C1-C10 alkyl. In some preferred embodiments, the alkylphenol compound used in the present invention is p-tert-butylphenol or p-tert-octylphenol, that is, in Formula I, R1 is tert-butyl (1,1-dimethylethyl) or tert-octyl (1,1,3,3-tetramethylbutyl).

[0051] The diene compound suitable for use in the present invention may have a structure shown in Formula IIA, Formula IIB or Formula IIC:

[0052]

[0053] In Formula IIA, R2 and R5 are each independently selected from H and C1-C4 alkyl, R3 and R4 are each independently selected from C1-C10 alkylene, a, b, c, d, e, f and g are each independently 0 or 1, c and e are not 0 at the same time, c is not 0 when b and d are both 1, and e is not 0 when d and f are both 1; In Formula IIB, R6 and R7 are each independently selected from H and C1-C4 alkyl, R8 and R9 are each independently selected from C1-C10 alkylene; In Formula IIC, R 10 and R 11 Each is independently selected from C1-C10 alkylene.

[0054] In some embodiments, in Formula IIA, R2 and R5 are each independently selected from H and methyl.

[0055] In some embodiments, in Formula IIA, R3 and R4 are each independently selected from C1-C4 alkylene.

[0056] In some embodiments, in Formula IIA, a, b, d, e, f and g are 0, c is 1, R3 is preferably C1-C4 alkylene (eg, methylene, 1,2-ethylene), and R2 and R5 are preferably each independently selected from H and methyl.

[0057] In some embodiments, in Formula IIA, a and g are 0, b, c, d, e and f are 1, R3 and R4 are preferably each independently selected from C1-C4 alkylene (e.g., methylene, 1,2-ethylene), and R2 and R5 are preferably each independently selected from H and methyl.

[0058] In some embodiments, in Formula IIA, a, b, f and g are 0, c, d and e are 1, R3 and R4 are preferably each independently selected from C1-C4 alkylene (e.g., methylene, 1,2-ethylene), and R2 and R5 are preferably each independently selected from H and methyl.

[0059] In some embodiments, in Formula IIA, a, b, c, e, f and g are 1, d is 1, R3 and R4 are preferably each independently selected from C1-C4 alkylene (e.g., methylene, 1,2-ethylene, 1,1-propylene), and R2 and R5 are preferably each independently selected from H and methyl.

[0060] In some embodiments, in Formula IIA, a, b, c, e, f and g are 1, d is 0, R3 and R4 are preferably each independently selected from C1-C4 alkylene (e.g., methylene, 1,2-ethylene, 1,1-propylene), and R2 and R5 are preferably each independently selected from H and methyl.

[0061] In some embodiments, in Formula IIB, R6 and R7 are each independently selected from H and methyl, and R8 and R9 are each independently selected from C1-C4 alkylene (eg, methylene, 1,2-ethylene).

[0062] In some embodiments, in Formula IIC, R 10 and R 11 Each is independently selected from C1-C4 alkylene (eg, methylene, 1,2-ethylene).

[0063] Examples of diene compounds suitable for use in the present invention include, but are not limited to, 1,5-hexadiene, diethylene glycol divinyl ether, diallyl ether, dipropylene glycol diacrylate 1,4-Butanediol dimethacrylate, diallyldimethylsilane, diallyl sulfide, etc. In some preferred embodiments, the diene compound used in the present invention is diethylene glycol divinyl ether, dipropylene glycol diacrylate, diallyldimethylsilane or diallyl sulfide.

[0064] The aldehyde compound suitable for the present invention can be one or more selected from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, benzaldehyde and furfural. In some preferred embodiments, the aldehyde compound used in the present invention is formaldehyde.

[0065] The molar ratio of the alkylphenol compound to the diene compound used to prepare the alkylphenol-formaldehyde resin of the present invention can be 1:(0.03-0.06), preferably 1:(0.04-0.05). The molar ratio of the alkylphenol compound to the aldehyde compound used to prepare the alkylphenol-formaldehyde resin of the present invention can be 1:(0.6-0.9), preferably 1:(0.7-0.8). Controlling the ratio of the alkylphenol compound to the diene compound and the ratio of the alkylphenol compound to the aldehyde compound within the aforementioned range can make the alkylphenol-formaldehyde resin have better adhesion, lower rigidity and better compatibility with rubber, which is beneficial to reduce the compression fatigue heat generation of the vulcanized rubber.

[0066] The alkylphenol-formaldehyde resin of the present invention can be formed by reacting an alkylphenol compound, a diene compound and an aldehyde compound in a molar ratio of 1: (0.03-0.06): (0.6-0.9). In a preferred embodiment, the alkylphenol-formaldehyde resin of the present invention is formed by reacting an alkylphenol compound, a diene compound and an aldehyde compound in a molar ratio of 1: (0.04-0.05): (0.7-0.8); wherein the alkylphenol compound is preferably p-tert-butylphenol or p-tert-octylphenol, the diene compound is preferably diethylene glycol divinyl ether or dipropylene glycol diacrylate, and the aldehyde compound is preferably formaldehyde. The alkylphenol-formaldehyde resin formed by reacting an alkylphenol compound, a diene compound and an aldehyde compound in the aforementioned molar ratio has good adhesion, reduced rigidity, good compatibility with rubber, and is conducive to reducing compression fatigue heat generation of vulcanized rubber.

[0067] The softening point of the alkylphenol-formaldehyde resin of the present invention is preferably 90-145° C., such as 95° C., 100° C., 110° C., 120° C., 130° C., 140° C. The free alkylphenol compound content of the alkylphenol-formaldehyde resin of the present invention is preferably ≤5.1%, such as 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%.

[0068] The preparation method of the diene compound-modified alkylphenol-formaldehyde resin of the present invention comprises the following steps:

[0069] (1) allowing an alkylphenol compound and a diene compound to undergo a Friedel-Crafts reaction to obtain a prepolymer;

[0070] (2) subjecting the prepolymer obtained in step (1), the alkylphenol compound and the aldehyde compound to a condensation polymerization reaction to obtain a diene compound-modified alkylphenol-formaldehyde resin.

[0071] In step (1), preferably, an excess amount of alkylphenol compound is added (ie, the molar ratio of the added alkylphenol compound to the diene compound is > 2:1) so that the double bonds of the diene compound are completely consumed.

[0072] In some embodiments, the alkylphenol compound has a structure shown in Formula I, the diene compound has a structure shown in Formula IIA, an excess of the alkylphenol compound is added in step (1), and the resulting prepolymer has a structure shown in Formula IIIA. The Friedel-Crafts reaction occurring in step (1) is as follows:

[0073]

[0074] R1, R2, R3, R4, R5 and a, b, c, d, e, f, g in Formula I, Formula IIA and Formula IIIA are as described in any embodiment herein.

[0075] In some embodiments, the alkylphenol compound has a structure as shown in Formula I, the prepolymer has a structure as shown in Formula IIIA, and the exemplary structural formula of the alkylphenol-formaldehyde resin of the present invention generated by the polycondensation of the alkylphenol compound, the prepolymer and the aldehyde compound in step (2) is as shown in Formula IVA:

[0076]

[0077] R1, R2, R3, R4, R5 and a, b, c, d, e, f, g in Formula IVA are as described in any embodiment herein, and x and y are the number of repeating units.

[0078] In some embodiments, the alkylphenol compound has a structure shown in Formula I, the diene compound has a structure shown in Formula IIB, an excess of the alkylphenol compound is added in step (1), and the resulting prepolymer has a structure shown in Formula IIIB. The Friedel-Crafts reaction occurring in step (1) is as follows:

[0079]

[0080] R1, R6, R7, R8, and R9 in Formula I, Formula IIB, and Formula IIIB are as described in any embodiment herein.

[0081] In some embodiments, the alkylphenol compound has a structure as shown in Formula I, the prepolymer has a structure as shown in Formula IIIB, and the exemplary structural formula of the alkylphenol-formaldehyde resin of the present invention generated by the polycondensation of the alkylphenol compound, the prepolymer and the aldehyde compound in step (2) is as shown in Formula IVB:

[0082]

[0083] R1, R6, R7, R8, and R9 in Formula IVB are as described in any embodiment herein, and x and y are the number of repeating units.

[0084] In some embodiments, the alkylphenol compound has a structure shown in Formula I, the diene compound has a structure shown in Formula IIC, an excess of the alkylphenol compound is added in step (1), and the resulting prepolymer has a structure shown in Formula IIIC. The Friedel-Crafts reaction occurring in step (1) is as follows:

[0085]

[0086] R1, R2 in Formula I, Formula IIC and Formula IIIC 10 , R 11 As described in any embodiment herein.

[0087] In some embodiments, the alkylphenol compound has a structure as shown in Formula I, the prepolymer has a structure as shown in Formula IIIC, and the exemplary structural formula of the alkylphenol-formaldehyde resin of the present invention generated by the polycondensation of the alkylphenol compound, the prepolymer and the aldehyde compound in step (2) is as shown in Formula IVC:

[0088]

[0089] R1 and R in formula IVC 10 , R 11 As described in any of the embodiments herein, x and y are the number of repeating units.

[0090] The reaction of step (1) and step (2) is carried out in the presence of an acidic catalyst. Available acidic catalysts can be various known acids that can be used as catalysts for preparing phenolic resins, including organic acids and inorganic acids, such as p-toluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, benzene disulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, sulfuric acid, phosphoric acid, etc., preferably p-toluenesulfonic acid. The amount of the acidic catalyst can be 0.2 mol% to 1 mol%, such as 0.5 mol%, of the amount of the phenolic compound. The reaction temperature of step (1) can be 80 to 140°C, such as 100°C, 110°C, 120°C, and the reaction time can be 10 to 200 min, such as 30 min, 45 min, 60 min, 90 min, 120 min. The reaction temperature of step (2) can be 90 to 180°C, such as 95°C, 100°C, 120°C, 150°C, and the reaction time can be 10 min to 12 h, such as 30 min, 1 h, 2 h, 3 h, 4 h, 5 h. When an excess of alkylphenol compound is added in step (1), unreacted alkylphenol compound and prepolymer exist in the obtained reaction system. In step (2), alkylphenol compound can be optionally added to the reaction system obtained in step (1) according to the amount of alkylphenol compound added in step (1), and then aldehyde compound is added to carry out polycondensation reaction. After the reaction in step (2) is completed, a quencher can be added to quench the reaction, and then water and free alkylphenol compound are removed by reduced pressure distillation to obtain the alkylphenol-formaldehyde resin of the present invention. The available quencher can be an organic base or an inorganic base, preferably triethanolamine.

[0091] In some embodiments, the alkylphenol-formaldehyde resin of the present invention is prepared by the following method: an excess of an alkylphenol compound and an acidic catalyst are melted, and a certain amount of a diene compound is added to react until the double bonds are completely consumed; unreacted alkylphenol compounds and prepolymers exist in the system; then an aldehyde compound is added dropwise for condensation polymerization, and if necessary, the alkylphenol compound can be added before polymerization; water and free alkylphenol compounds are removed by reduced pressure distillation; a base is added for neutralization, the reaction is quenched and the material is discharged.

[0092] The present invention has the following beneficial effects: the present invention introduces a flexible segment into the main chain of an alkylphenol-formaldehyde resin by means of a diene compound, and the obtained modified alkylphenol-formaldehyde resin is applied to rubber, and while exerting a viscosity-increasing effect, it also realizes the function of reducing compression fatigue heat generation. Therefore, the present invention also provides the use of the alkylphenol-formaldehyde resin of the present invention in improving the surface viscosity of rubber and / or reducing the compression fatigue heat generation of rubber.

[0093] The alkylphenol-formaldehyde resin of the present invention can be used as a tackifying resin in rubber, and while improving the surface viscosity of the rubber, it can also reduce the compression fatigue heat generation of the rubber. Therefore, the present invention also includes a rubber composition, which includes the alkylphenol-formaldehyde resin of the present invention. The rubber composition of the present invention can be a tire rubber composition.

[0094] The raw material of rubber composition generally includes diene elastomer, reinforcing filler, antioxidant and cross-linking agent. The raw material of rubber composition of the present invention also includes alkylphenol-formaldehyde resin of the present invention as tackifying resin. Herein, rubber composition includes unvulcanized rubber and vulcanized rubber. Unvulcanized rubber can be made into vulcanized rubber through vulcanization (curing).

[0095] In the raw materials of the rubber composition of the present invention, based on 100 parts by weight of the diene elastomer, the content of the reinforcing filler may be 30-70 parts by weight, the content of the antioxidant may be 0.1-8 parts by weight, the content of the crosslinking agent may be 0.5-10 parts by weight, and the content of the alkylphenol-formaldehyde resin of the present invention as a tackifying resin may be 1-5 parts by weight, for example, 2±0.5 parts by weight. Herein, unless otherwise specified, parts by weight are calculated relative to 100 parts by weight of the diene elastomer contained in the raw materials of the rubber composition.

[0096] Herein, diene elastomer refers to an elastomer whose monomers contain dienes (such as butadiene, isoprene). Suitable diene elastomers for the present invention can be various diene elastomers known in the art, including but not limited to one or more selected from natural rubber (NR), butadiene rubber (BR), isoprene rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), isoprene / butadiene copolymer, isoprene / styrene copolymer and isoprene / butadiene / styrene copolymer. In some embodiments, in the raw materials of the rubber composition of the present invention, the diene elastomer is natural rubber.

[0097] The antioxidant applicable to the present invention can be various antioxidants commonly used in rubber compositions, such as antioxidant 6PPD. The raw materials of the rubber composition of the present invention usually include 0.1-8 parts by weight, preferably 1-5 parts by weight, more preferably 2±0.5 parts by weight of antioxidant.

[0098] Reinforcing fillers suitable for the present invention can be conventional reinforcing fillers for rubber compositions, including but not limited to one or more selected from carbon black, white carbon black, titanium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, clay and talcum. The raw materials of the rubber composition generally include 30-70 parts by weight, preferably 40-60 parts by weight of reinforcing fillers. In some embodiments, in the rubber composition of the present invention, the reinforcing filler is carbon black.

[0099] The crosslinking agent may be sulfur. The raw materials of the rubber composition generally contain 0.5-10 parts by weight, preferably 1-5 parts by weight, for example 2-3 parts by weight of the crosslinking agent. In some embodiments, in the rubber composition of the present invention, the crosslinking agent is insoluble sulfur (referred to as insoluble sulfur).

[0100] The raw material of rubber composition of the present invention may also include other ingredients commonly used in rubber composition, including but not limited to one or more of activating agent, accelerator, softener and rubber adhesive. The respective amounts of activating agent, accelerator, softener and rubber adhesive may be conventional amounts in the art.

[0101] The activator can accelerate the vulcanization speed, improve the thermal conductivity, wear resistance, tear resistance of the rubber, etc. The activator can be zinc oxide. In some embodiments, the raw materials of the rubber composition of the present invention include an activator, such as zinc oxide. The raw materials of the rubber composition of the present invention can include 0-10 parts by weight, preferably 2-10 parts by weight, for example 4±1 parts by weight of an activator, such as zinc oxide.

[0102] Accelerator is generally a vulcanization accelerator, and can be selected from sulfonamide vulcanization accelerator, thiazole vulcanization accelerator, thiuram vulcanization accelerator, thiourea vulcanization accelerator, guanidine vulcanization accelerator, dithiocarbamate vulcanization accelerator, aldehyde amine vulcanization accelerator, aldehyde ammonia vulcanization accelerator, imidazoline vulcanization accelerator and xanthate vulcanization accelerator One or more. For example, accelerator can be accelerator CBS (N- cyclohexyl -2- benzothiazole sulfonamide). In some embodiments, the raw material of the rubber composition of the present invention includes accelerator, such as accelerator CBS. The raw material of the rubber composition of the present invention can include 0-2 weight portion, preferably 0.2-2 weight portion, for example 0.6 ± 0.1 weight portion of accelerator, such as accelerator CBS.

[0103] The effect of softening agent is mainly to improve the performances such as processability. Softening agent can include petroleum softening agent, such as naphthenic oil, aromatic oil, process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt and vaseline etc., and can also include fatty oil softening agent, such as stearic acid, castor oil, linseed oil, rapeseed oil, coconut oil, wax (such as beeswax, carnauba wax and lanolin), tall oil, linoleic acid, palmitic acid and lauric acid etc. In some embodiments, the raw material of rubber composition of the present invention includes petroleum softening agent (such as naphthenic oil) and fatty oil softening agent (such as stearic acid). The raw material of rubber composition of the present invention can include 0-20 weight portion, preferably 1-10 weight portion, more preferably 2-8 weight portion, for example 6 ± 1 weight portion of operating oil, for example naphthenic oil. The raw materials of the rubber composition of the present invention may contain 0-5 parts by weight, preferably 0.5-4 parts by weight, more preferably 1-3 parts by weight, for example 2±0.5 parts by weight, 2±0.2 parts by weight of a fatty oil softener such as stearic acid.

[0104] The rubber adhesive suitable for the present invention can be a rubber adhesive commonly used in rubber compositions, such as rubber adhesive R-80, rubber adhesive RA, etc. The raw materials of the rubber composition of the present invention can include 0-10 parts by weight, preferably 0.5-10 parts by weight, such as 2-8 parts by weight, 4-6 parts by weight of rubber adhesive. In some embodiments, the raw materials of the rubber composition of the present invention include 0.5-5 parts by weight, such as 2±0.5 parts by weight of rubber adhesive R-80, and 0.5-5 parts by weight, such as 2.5±0.5 parts by weight of rubber adhesive RA.

[0105] In some embodiments, the raw materials of the rubber composition of the present invention include or consist of the following components: diene elastomer, tackifying resin, crosslinking agent, reinforcing filler, active agent, softener, antioxidant, rubber binder and accelerator.

[0106] The unvulcanized rubber of the present invention can be prepared by a conventional rubber mixing method, for example, by a two-stage mixing method: a first stage of mixing in an internal mixer, mixing other raw materials except the crosslinking agent and the accelerator to obtain a masterbatch, and the discharge temperature can be 150±10°C; a second stage of mixing in an open mixer, mixing the masterbatch, the crosslinking agent and the accelerator obtained in the first stage to obtain the unvulcanized rubber.

[0107] The unvulcanized rubber of the present invention can be vulcanized by conventional vulcanization methods to obtain vulcanized rubber. The vulcanization temperature is usually 130°C-200°C, for example, 150±2°C. The vulcanization time depends on the vulcanization temperature, the vulcanization system and the vulcanization kinetics, and is usually 15-60 minutes, for example, 30±5 minutes. Before vulcanization, the unvulcanized rubber obtained by mixing can be conventionally sheeted.

[0108] The present invention also provides a rubber product, wherein part or all of the rubber product is the rubber composition described in any embodiment of the present invention, or is prepared from the rubber composition described in any embodiment of the present invention. The rubber product can be a tire, a rubber shoe, a sealing strip, a sound insulation board, a vibration-absorbing pad, etc.

[0109] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples can all be purchased through commercial routes.

[0110] In the present invention, the softening point of the prepared resin is measured according to GB / T 4507.

[0111] In the present invention, the free alkylphenol content is determined by gas chromatography.

[0112] Example 1

[0113] In a 250 ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.4 mol of p-tert-butylphenol, 0.002 mol of p-toluenesulfonic acid, and 0.02 mol of diethylene glycol divinyl ether, and prepolymerize at 120°C for 1 hour. Then add 0.32 mol of formaldehyde dropwise for polycondensation, and keep at 100°C for another hour. Heat to 150°C and distill at normal pressure for 3 hours to remove a large amount of water. Quench with 0.002 mol of triethanolamine, and remove trace amounts of water by vacuum distillation to obtain a modified alkyl phenolic resin (yield 95%). The prepared modified alkyl phenolic resin has a softening point of 141.2°C and a free alkylphenol content of 0.28%, which is recorded as resin A1.

[0114] Example 2

[0115] In a 250ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.4mol of p-tert-butylphenol, 0.002mol of p-toluenesulfonic acid, and 0.02mol of diethylene glycol divinyl ether, and prepolymerize at 120°C for 1 hour. Then add 0.28mol of formaldehyde dropwise for polycondensation, and keep at 100°C for another hour. Heat to 150°C and distill at normal pressure for 3h to remove a large amount of water. Quench with 0.002mol of triethanolamine, and remove trace amounts of water by vacuum distillation to obtain a modified alkylphenol-formaldehyde resin (yield 96%). The prepared modified alkylphenol-formaldehyde resin has a softening point of 126.4°C and a free alkylphenol content of 0.04%, which is recorded as resin A2.

[0116] Example 3

[0117] In a 250 ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.5 mol of p-tert-butylphenol, 0.0025 mol of p-toluenesulfonic acid, and 0.02 mol of dipropylene glycol diacrylate, and prepolymerize at 120°C for 1 hour. Then add 0.35 mol of formaldehyde dropwise for polycondensation, and keep at 100°C for another hour. Heat to 150°C and distill at atmospheric pressure for 3 hours to remove a large amount of water. Quench with 0.0025 mol of triethanolamine, and remove trace amounts of water by vacuum distillation to obtain a modified alkylphenol-formaldehyde resin (yield 96%). The prepared modified alkylphenol-formaldehyde resin has a softening point of 121.2°C and a free alkylphenol content of 0.12%, which is recorded as resin A3.

[0118] Example 4

[0119] In a 250 ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.5 mol of p-tert-butylphenol, 0.0025 mol of p-toluenesulfonic acid, and 0.02 mol of dipropylene glycol diacrylate, and prepolymerize at 120°C for 1 hour. Then add 0.40 mol of formaldehyde dropwise for polycondensation, and keep at 100°C for another hour. Heat to 150°C and distill at atmospheric pressure for 3 hours to remove a large amount of water. Quench with 0.0025 mol of triethanolamine, and remove trace amounts of water by vacuum distillation to obtain a modified alkylphenol-formaldehyde resin (yield 97%). The prepared modified alkylphenol-formaldehyde resin has a softening point of 124.8°C and a free alkylphenol content of 0.18%, which is recorded as resin A4.

[0120] Example 5

[0121] In a 250 ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.36 mol of p-tert-octylphenol, 0.0018 mol of p-toluenesulfonic acid, and 0.018 mol of diethylene glycol divinyl ether, and prepolymerize at 120°C for 45 minutes. Then add 0.26 mol of formaldehyde dropwise for polycondensation, and keep at 100°C for another hour. Heat to 150°C and distill at atmospheric pressure for 2 hours to remove a large amount of water. Quench with 0.0018 mol of triethanolamine, and remove trace amounts of water by vacuum distillation to obtain a modified alkyl phenolic resin (yield 97%). The prepared modified alkyl phenolic resin has a softening point of 99.3°C and a free alkylphenol content of 2.35%, which is recorded as resin A5.

[0122] Example 6

[0123] In a 250 ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, 0.36 mol of p-tert-octylphenol, 0.0018 mol of p-toluenesulfonic acid, and 0.015 mol of dipropylene glycol diacrylate were added, and prepolymerized at 120°C for 45 minutes. Then 0.29 mol of formaldehyde was added dropwise for polycondensation, and the mixture was kept at 100°C for another hour. The mixture was heated to 150°C and distilled at atmospheric pressure for 2 hours to remove a large amount of water. The mixture was quenched with 0.0018 mol of triethanolamine, and a modified alkylphenol-formaldehyde resin (yield 97%) was obtained after removing trace amounts of water by distillation under reduced pressure. The prepared modified alkylphenol-formaldehyde resin had a softening point of 97.0°C and a free alkylphenol content of 4.56%, and was recorded as resin A6.

[0124] Example 7

[0125] In a 250 ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, 0.36 mol of p-tert-octylphenol, 0.0018 mol of p-toluenesulfonic acid, and 0.015 mol of diallyl sulfide were added, and the mixture was prepolymerized at 120°C for one hour. Then, the temperature was slowly lowered while 0.29 mol of formaldehyde (37% aqueous solution) was added dropwise for polycondensation, and the mixture was kept at 100°C for another hour. The mixture was heated to 150°C and distilled at atmospheric pressure for 2 hours to remove a large amount of water. The mixture was quenched with 0.0018 mol of triethanolamine, and a trace amount of water was removed by distillation under reduced pressure to obtain a modified alkylphenol-formaldehyde resin (yield 96%). The prepared modified alkylphenol-formaldehyde resin had a softening point of 96.0°C and a free alkylphenol content of 5.02%, and was recorded as resin A7.

[0126] Example 8

[0127] In a 250 ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.36 mol of p-tert-octylphenol, 0.0018 mol of p-toluenesulfonic acid, and 0.015 mol of diallyldimethylsilane, and keep it at 100-110°C for one hour for prepolymerization. Then add 0.29 mol of formaldehyde (37% aqueous solution) dropwise for polycondensation, and keep it at 95-100°C for another hour. Heat to 150°C and distill at atmospheric pressure for 2 hours to remove a large amount of water. Quench with 0.0018 mol of triethanolamine, and remove trace amounts of water by vacuum distillation to obtain a modified alkylphenol-formaldehyde resin (yield 97%). The prepared modified alkylphenol-formaldehyde resin has a softening point of 90.7°C and a free alkylphenol content of 4.17%, which is recorded as resin A8.

[0128] Comparative Example 1

[0129] In a 250ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.60mol of p-tert-butylphenol and 0.003mol of p-toluenesulfonic acid, and heat to melt. Then add 0.44mol of formaldehyde dropwise for polycondensation reaction, and keep warm at 100℃ for 1 hour. Then heat to 150℃ and distill at normal pressure for 2h to remove a large amount of water. Quench with 0.003mol of triethanolamine, and remove trace water by vacuum distillation to obtain alkylphenol-formaldehyde resin (yield 95%). The prepared alkylphenol-formaldehyde resin has a softening point of 122.5℃ and a free alkylphenol content of 0.29%, which is recorded as resin B1.

[0130] Comparative Example 2

[0131] In a 250ml round-bottom four-necked flask equipped with a mechanical stirrer, a thermometer, and a reflux condenser, add 0.46mol of p-tert-octylphenol and 0.0023mol of p-toluenesulfonic acid, and heat to melt. Then add 0.39mol of formaldehyde dropwise for polycondensation reaction, and keep warm at 100°C for 1 hour. Then heat to 150°C and distill at normal pressure for 2h to remove a large amount of water. Quench with 0.0023mol of triethanolamine, and remove trace amounts of water by vacuum distillation to obtain an alkylphenol-formaldehyde resin (yield 98%). The prepared alkylphenol-formaldehyde resin has a softening point of 90.7°C and a free alkylphenol content of 4.85%, which is recorded as resin B2.

[0132] Application Examples

[0133] In order to investigate the effect of diene compound copolymer-modified tackifying resin on the surface tackification of unvulcanized rubber sheets, as well as the influence of resin modification on rubber processing performance and mechanical properties, rubber compositions 1-10 were prepared using resins A1-A8 and B1-B2 as tackifying resins according to the following rubber formula and rubber mixing process.

[0134] Rubber formula:

[0135] 100 parts by weight of natural rubber; 2.0 parts by weight of tackifying resin; 60 parts by weight of carbon black; 4.0 parts by weight of zinc oxide; 2.0 parts by weight of stearic acid; 2.0 parts by weight of antioxidant 6PPD; 6.0 parts by weight of naphthenic oil; 2.0 parts by weight of rubber adhesive R-80; 0.6 parts of accelerator CBS; 2.3 parts of rubber adhesive RA; 2.3 parts of insoluble sulfur. In rubber compositions 1-10, resins A1, A2, A3, A4, A5, A6, B1, B2, A7, and A8 are used as tackifying resins, respectively.

[0136] Rubber mixing process:

[0137] Perform one-stage mixing in an internal mixer: add the rubber components except sulfur and accelerator into the internal mixer, mix to 135℃, lift the pressure roller, continue mixing to 150℃ to discharge the rubber, and obtain the masterbatch. Perform two-stage mixing in an open mixer: take the masterbatch and roll it, add sulfur and accelerator, and perform thin pass and roll operations to make the rubber surface smooth. The rubber used for surface viscosity test is not vulcanized. The rubber used for vulcanized rubber performance test must be vulcanized (vulcanization conditions: 151℃, 30min).

[0138] Test Example 1

[0139] The surface viscosity of the unvulcanized rubber composition was tested according to GB / T 4852-2002. The adhesion of each sample was tested using the pressure-sensitive adhesive tape initial adhesion test method (rolling ball method). A steel ball was placed at a fixed height on a fixed inclined plane, and the steel ball was rolled and passed through the tape using the drop to characterize the interaction between the rubber and the steel ball. The initial adhesion of the rubber was evaluated based on the maximum steel ball size that could be adhered to the adhesive surface of a specified length. The results are shown in Table 1.

[0140] Table 1: Viscosity (unit: DN) and retention rate of rubber compositions

[0141]

[0142]

[0143] As can be seen from Table 1, both the diene-modified alkylphenol-formaldehyde resin and the unmodified alkylphenol-formaldehyde resin have the effect of improving the surface viscosity of the rubber, and whether the diene compound is modified or not has no obvious effect on the surface viscosity-enhancing effect of the alkylphenol-formaldehyde resin.

[0144] Test Example 2

[0145] The properties of the vulcanized rubber composition were tested according to the following performance test method, and the results are shown in Table 2:

[0146] Mooney and vulcanization properties are measured with reference to GB / T 16584-1996 and GB / T 1233-2008;

[0147] The mechanical properties are tested according to GB / T 528-2009;

[0148] Compression fatigue temperature rise is tested according to GB / T1687-93;

[0149] The thermal oxidation aging test was carried out according to GB / T 3512-2014, and the aging conditions were 100°C×48h.

[0150] Table 2: Performance test results of rubber compositions

[0151]

[0153]

[0154] As can be seen from Table 2, compared with rubber composition 7 (containing resin B1), rubber composition 2 (containing resin A2) and rubber composition 4 (containing resin A4) have lower Mooney viscosity and lower compression fatigue temperature rise; compared with rubber composition 8 (containing resin B2), rubber composition 5 (containing resin A5) and rubber composition 6 (containing resin A6) have lower Mooney viscosity and lower compression fatigue temperature rise.

[0155] It can be seen from Tables 1 and 2 that the present invention uses diene compounds to modify alkylphenol-formaldehyde resins, which can achieve the effect of reducing compression fatigue temperature rise (i.e., reducing compression fatigue heat generation), while basically not affecting the surface viscosity, processing performance and physical properties of the rubber.

Claims

1. An alkylphenol-formaldehyde resin, characterized in that The alkylphenol-formaldehyde resin is formed by the reaction of an alkylphenol compound, a diene compound and an aldehyde compound; The alkylphenol compound is a compound of formula I: In formula I, R1 is selected from C1-C20 alkyl; The diene compound is selected from the group consisting of a compound of formula IIA, a compound of formula IIB and a compound of formula IIC: In Formula IIA, R2 and R5 are each independently selected from H and C1-C4 alkyl, R3 and R4 are each independently selected from C1-C10 alkylene, a, b, c, d, e, f and g are each independently 0 or 1, c and e are not 0 at the same time, c is not 0 when b and d are both 1, and e is not 0 when d and f are both 1; In Formula IIB, R6 and R7 are each independently selected from H and C1-C4 alkyl, R8 and R9 are each independently selected from C1-C10 alkylene; In Formula IIC, R 10 and R 11 Each is independently selected from C1-C10 alkylene.

2. The alkylphenol-formaldehyde resin according to claim 1, wherein In formula I, R1 is selected from C1-C10 alkyl; preferably, R1 is selected from tert-butyl and tert-octyl.

3. The alkylphenol-formaldehyde resin according to claim 1, wherein In Formula IIA, R2 and R5 are each independently selected from H and methyl, R3 and R4 are each independently selected from C1-C4 alkylene; in Formula IIB, R6 and R7 are each independently selected from H and methyl, R8 and R9 are each independently selected from C1-C4 alkylene; in Formula IIC, R 10 and R 11 Each is independently selected from C1-C4 alkylene.

4. The alkylphenol-formaldehyde resin according to claim 1, wherein The diene compound is selected from one or more of 1,5-hexadiene, diethylene glycol divinyl ether, diallyl ether, dipropylene glycol diacrylate, 1,4-butanediol dimethacrylate, diallyl dimethyl silane and diallyl sulfide, preferably selected from one or more of diethylene glycol divinyl ether, dipropylene glycol diacrylate, diallyl dimethyl silane and diallyl sulfide; and / or The aldehyde compound is selected from one or more of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, benzaldehyde and furfural, preferably formaldehyde.

5. The alkylphenol-formaldehyde resin according to claim 1, wherein The molar ratio of the alkylphenol compound to the diene compound is 1:(0.03-0.06), preferably 1:(0.04-0.05); and / or The molar ratio of the alkylphenol compound to the aldehyde compound is 1:(0.6-0.9), preferably 1:(0.7-0.8).

6. The alkylphenol-formaldehyde resin according to claim 1, wherein The softening point of the alkylphenol-formaldehyde resin is 90-145° C.; and / or the free alkylphenol compound content of the alkylphenol-formaldehyde resin is ≤5.1%.

7. A method for preparing the alkylphenol-formaldehyde resin according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: (1) subjecting the alkylphenol compound to a Friedel-Crafts reaction with the diene compound so that the double bonds of the diene compound are completely consumed to obtain a prepolymer; (2) subjecting the alkylphenol compound, the aldehyde compound and the prepolymer obtained in step (1) to a condensation polymerization reaction to obtain the alkylphenol-formaldehyde resin.

8. The method according to claim 7, characterized in that The method has one or more of the following features: One molecule of the prepolymer is formed by the reaction of at least one molecule of the diene compound and at least two molecules of the alkylphenol compound; preferably, one molecule of the prepolymer is formed by the reaction of one molecule of the diene compound and two molecules of the alkylphenol compound; The reaction of step (1) and step (2) is carried out in the presence of an acidic catalyst; the acidic catalyst is preferably selected from one or more of p-toluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, benzene disulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, sulfuric acid and phosphoric acid, more preferably p-toluenesulfonic acid; the amount of the acidic catalyst is preferably 0.2 mol% to 1 mol% of the amount of the phenolic compound; The reaction temperature of step (1) is 80-140° C., and the reaction time is 10-200 min. The reaction temperature of step (2) is 90-180° C., and the reaction time is 10 min-12 h; In step (1), the molar ratio of the alkylphenol compound to the diene compound is greater than 2:1, and unreacted alkylphenol compound and the prepolymer exist in the obtained reaction system; in step (2), the alkylphenol compound is first optionally added to the reaction system obtained in step (1), and then the aldehyde compound is slowly added to carry out a condensation reaction; After the reaction in step (2) is completed, a quenching agent is added to quench the reaction, and water and free alkylphenol compounds are removed by distillation under reduced pressure; the quenching agent is preferably selected from one or more of an inorganic base and an organic base, and more preferably triethanolamine.

9. A rubber composition, characterized in that: The rubber composition contains a diene elastomer and an alkylphenol-formaldehyde resin as claimed in any one of claims 1 to 6 as a tackifying resin; preferably, the mass ratio of the diene elastomer to the alkylphenol-formaldehyde resin is 100:(1 to 5).

10. Use of the alkylphenol-formaldehyde resin according to any one of claims 1 to 6 for increasing the surface viscosity of rubber and / or reducing the compression fatigue heat generation of rubber.

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