Resorcinol-cinnamyl aldehyde resin, preparation method thereof, modified vulcanized rubber composition and application

Abstract

The invention discloses resorcinol-cinnamyl aldehyde resin, a preparation method of the resorcinol-cinnamyl aldehyde resin, a modified vulcanized rubber composition and application of the modified vulcanized rubber composition, and relates to novel phenolic resin, in particular to environment-friendly phenolic resin with alkyl resorcinol and hydroxyl cinnamyl aldehyde as raw materials. The preparation method disclosed by the invention is simple in process, cinnamyl aldehyde extracted from bio-based is used in the process, the sustainable development concept is met, the environment-friendly characteristic of cinnamyl aldehyde is utilized, and the influence of formaldehyde on human bodies in the traditional resin production process is avoided. The invention also relates to application of the rubber composition in the rubber industry, and the prepared rubber product has excellent mechanical properties.

Description

Technical Field

[0001] The invention relates to the field of phenolic resins for rubber industry, and in particular to a resorcinol-cinnamaldehyde resin, a preparation method thereof, a modified vulcanized rubber composition and application thereof. Background Art

[0002] Resorcinol formaldehyde resin is a high-performance phenolic resin produced by the polycondensation reaction of resorcinol and formaldehyde under certain conditions. It is currently widely used in many fields such as the rubber industry and the wood industry, mainly as an adhesive, reinforcing agent or modifier. It can significantly improve the physical properties of rubber products, such as heat resistance, chemical resistance, and anti-aging performance, and has great application capabilities, especially in automobile tires, hoses, synthetic fibers and other products.

[0003] Although resorcinol formaldehyde resin is widely used in the rubber field, there are certain shortcomings in its production and use. The most critical shortcoming is the formaldehyde contained in the product. Formaldehyde is one of the key raw materials for the production of this resin. If you want to obtain the final product, it will cause great risks to the environment and human health. With the rapid development of the times, industrial requirements are also increasing. At present, the material industry advocates the concept of green, non-toxic and sustainable development. Therefore, finding aldehyde substances to replace formaldehyde or reducing the use of formaldehyde is one of the main directions of the development of phenolic resin.

[0004] In recent years, industry has developed rapidly and wants to achieve higher and better progress. The current focus is to achieve breakthroughs in line with the concept of green, non-toxic and sustainable development. At present, biomass extraction molecules have gradually become one of the key directions of development because they come from organisms such as plants, animals and microorganisms. Compared with traditional non-renewable energy sources such as fossil fuels, biomass extraction molecules are renewable and can be widely extracted from biomass, reducing dependence on current limited resources and meeting the requirements of sustainable development. At the same time, the commonly used solvents in the biomass extraction process are usually green solvents such as water, ethanol, and acetone, which are relatively non-toxic and harmless. With the advancement of technology, the extraction process is constantly optimized. New extraction technologies such as ultrasound-assisted extraction, microwave-assisted extraction, and enzymatic extraction can complete extraction at lower temperatures and in a shorter time, reducing energy consumption, improving efficiency, and reflecting the characteristics of green environmental protection.

[0005] Hydroxycinnamaldehyde is a class of organic compounds containing the basic structure of hydroxyl and cinnamaldehyde. It is widely present in nature, and many plants can synthesize and contain such compounds. For example, cinnamon contains a certain amount of 4-hydroxycinnamaldehyde. In addition, it is also found in some fruits, vegetables and medicinal plants. It has a wide range of chemical reactivity. Compared with formaldehyde, the impact of hydroxycinnamaldehyde as a biomass extraction component on human health is greatly reduced, while maintaining or even improving the performance of the resin. In recent years, there have been reports on the reaction of cinnamaldehyde with phenolic substances. And the current extraction conditions for hydroxycinnamaldehyde are also relatively simple. CN202310199112.3 mentions soaking cinnamon leaf powder in a solvent, ultrasonic treatment steam condensation, oil and water separation to obtain cinnamon oil, adding an antioxidant and then distilling and separating to obtain cinnamaldehyde. There are also schemes such as extraction by water enzyme method and supercritical CO2.

[0006] Therefore, using hydroxycinnamaldehyde to replace formaldehyde to synthesize resorcinol formaldehyde resin is a possible innovation direction. Hydroxycinnamaldehyde can undergo a condensation reaction similar to phenolic resin with resorcinol to form a new type of phenolic resin, which not only retains the characteristics of traditional resorcinol formaldehyde resin, but also avoids the harm of formaldehyde to the environment and health. Summary of the invention

[0007] The purpose of the present invention is to provide a resorcinol-cinnamaldehyde resin, a preparation method thereof, a modified vulcanized rubber composition and application thereof, wherein hydroxycinnamaldehyde is used to replace formaldehyde to react with resorcinol in the production process to generate a novel environmentally friendly phenolic resin, thereby reducing the impact on the environment and personnel in the production process.

[0008] One of the purposes of the present invention is to provide a novel resorcinol-cinnamaldehyde resin having the following structural formula:

[0009]

[0010] In formula (1), R is independently selected from hydrogen, a C2-C10 alkyl group, and an aralkyl group containing a C2-C6 substituent, R1 is an ortho- or para-hydroxyl group, and m is an integer of 1-50.

[0011] The second object of the present invention is to provide a method for preparing a novel resorcinol-cinnamaldehyde resin, which comprises the following steps in sequence:

[0012] Step S1, heating resorcinol to 90-150° C., then adding an acidic catalyst, stirring evenly, at a speed of 100-200 rpm, and dropping an unsaturated olefin compound to cause an alkylation reaction between resorcinol and the olefin compound;

[0013] Step S2, adding hydroxycinnamaldehyde compounds and reflux under heat preservation;

[0014] Step S3, after the reflux is completed, the temperature is raised to 100-180° C. and atmospheric distillation is performed for 30-100 minutes;

[0015] Step S4, after the atmospheric pressure reflux is completed, a terminator is added, followed by vacuum distillation, the vacuum degree is -0.01 to -0.1 MPa, and the vacuum distillation time is 10 to 90 min, to obtain the resorcinol-cinnamaldehyde resin of the following formula (1).

[0016] Preferably, in the preparation method of the above-mentioned resorcinol-cinnamaldehyde resin, the hydroxycinnamaldehyde compounds are 2-hydroxycinnamaldehyde and 4-hydroxycinnamaldehyde; the molar ratio of the resorcinol to the hydroxycinnamaldehyde compounds is 1:0.2-0.75, preferably 1:0.45-0.65.

[0017] Preferably, in the preparation method of the above-mentioned resorcinol-cinnamaldehyde resin, the unsaturated olefin compound is at least one of styrene, divinylbenzene, p-methylstyrene, vinyltoluene or α-methylstyrene, and the molar ratio of the resorcinol to the unsaturated olefin compound is 1:0.1~0.95, preferably 1:0.35~0.6.

[0018] Preferably, in the preparation method of the above-mentioned resorcinol-cinnamaldehyde resin, the acidic catalyst includes at least one of an inorganic acid and an organic acid, the inorganic acid includes sulfuric acid, hydrobromic acid, phosphoric acid, and hydrochloric acid; the organic acid includes benzenesulfonic acid, dodecylsulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, phenolsulfonic acid, chlorobenzenesulfonic acid, and sodium sulfonate, and the amount of the acidic catalyst is 0.1 to 10% of the mass of the resorcinol, preferably 0.5 to 4%.

[0019] Preferably, in the preparation method of the above-mentioned resorcinol-cinnamaldehyde resin, the terminator is an organic base, an alkali metal or a hydroxide, including at least one of triethylamine, diethylamine, potassium hydroxide, sodium hydroxide, and calcium hydroxide, and the amount of the terminator is 0.1 to 8% by mass of the phenolic compound, preferably 0.5 to 4% by mass, and the phenolic compound includes resorcinol and alkylresorcinol.

[0020] Also disclosed is a modified vulcanized rubber composition, which comprises a rubber component selected from natural rubber or synthetic rubber, a methylene donor, and a methylene acceptor, wherein the methylene acceptor is the resorcinol-cinnamaldehyde resin prepared by the above method.

[0021] Preferably, in the above-mentioned modified vulcanized rubber composition, the rubber component is selected from at least one of isobutylene rubber and ethylene-propylene copolymer, polybutadiene, cis-1,4-polyisoprene, acrylonitrile and butadiene copolymer, acrylonitrile and isoprene copolymer, isobutylene rubber, isoprene and butadiene copolymer, and styrene and butadiene copolymer.

[0022] Also disclosed are applications of the modified vulcanized rubber composition, including tires, rubber hoses and belts, rubber seals and gaskets, shock absorbers, bridge bearings, flooring materials, roofing and waterproofing materials, conveyor belts, industrial hoses and belts, gloves and medical tubes, aircraft tires, seals and gaskets, diving suits and equipment.

[0023] The preparation method of the resorcinol-cinnamaldehyde resin proposed by the present invention adopts an acid catalyst and is prepared by polycondensation of resorcinol, an unsaturated olefin compound and hydroxycinnamaldehyde. The mechanical properties of the modified vulcanized rubber prepared by the present invention are improved. Meanwhile, no formaldehyde is involved in the production process of the resin, thereby reducing the pollution to the environment and the occupational health hazards to the on-site operators. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 41.6g of styrene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. After that, 59.3g of 4-hydroxycinnamaldehyde was added to the reaction bottle in a small amount and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 104°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 3.4%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.4:0.4

[0027] Example 2

[0028] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 41.6g of styrene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. After that, 74.1g of 4-hydroxycinnamaldehyde was added to the reaction bottle in a small amount and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 110°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 3.1%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.4:0.5

[0029] Example 3

[0030] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 41.6g of styrene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. Afterwards, 88.9g of 4-hydroxycinnamaldehyde was added to the reaction bottle in a small amount and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 119°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 2.0%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.4:0.6

[0031] Example 4

[0032] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 52.1g of styrene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. Afterwards, 59.3g of 4-hydroxycinnamaldehyde was added to the reaction bottle in small amounts and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 108°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 3.1%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.5:0.4

[0033] Example 5

[0034] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 62.5g of styrene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. After that, 59.3g of 4-hydroxycinnamaldehyde was added to the reaction bottle in a small amount and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 111°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 2.7%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.6:0.4

[0035] Example 6

[0036] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 41.6g of styrene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. After that, 59.3g of 2-hydroxycinnamaldehyde was added to the reaction bottle in small amounts and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 103°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 3.5%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 2-hydroxycinnamaldehyde is 1:0.4:0.4

[0037] Example 7

[0038] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 47.2g of vinyltoluene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. After that, 59.3g of 4-hydroxycinnamaldehyde was added to the reaction bottle in a small amount and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 102°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 3.4%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.4:0.4

[0039] Example 8

[0040] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 52g of divinylbenzene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. Afterwards, 59.3g of 4-hydroxycinnamaldehyde was added to the reaction bottle in a small amount and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 104°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 3.5%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.4:0.4

[0041] Example 9

[0042] In a 500mL four-necked round-bottom flask equipped with an agitator, a thermometer, a reflux condenser and a dropping funnel, 110.1g of resorcinol and 1.0g of p-toluenesulfonic acid were added in sequence, and the temperature was raised to 120-130°C. Then 47.2g of α-methylstyrene was added dropwise using a dropping funnel. During this process, the temperature must be strictly controlled between 125 and 135°C, and the dropwise addition time was between 30 and 45min. After the addition of styrene was completed, the temperature of the reaction mixture was maintained at 130°C and the reaction was continued for 20min. After that, 59.3g of 4-hydroxycinnamaldehyde was added to the reaction bottle in a small amount and multiple times, and then kept warm for 10-20min. Subsequently, 1.05g of a 20% NaOH aqueous solution was added to the reaction system to neutralize the p-toluenesulfonic acid catalyst. After neutralization, the temperature is raised to 150°C, and atmospheric distillation is started during the temperature rise period. Finally, vacuum distillation is performed for 10 to 90 minutes at a vacuum degree of -0.01 to -0.1 MPa, thereby obtaining the resorcinol-cinnamaldehyde resin of formula (1). The SP of the resin is 101°C; HPLC analysis shows that the mass fraction of free resorcinol in the resin is 3.6%. In the entire reaction process, the molar ratio of resorcinol, styrene, and 4-hydroxycinnamaldehyde is 1:0.4:0.4

[0043] The resorcinol-cinnamaldehyde resin prepared in the embodiment is compared with the resin products on the market to evaluate its effect in the rubber composition. Since the structure of hydroxycinnamaldehyde contains double bonds, it can increase the vulcanization speed. The effect of the resin on the rubber performance is verified by testing the vulcanization scorch performance. The composition of the rubber composition is as follows:

[0044] Serial number Component name Quality score 1 Natural rubber, NR 100 2 Carbon Black N365 55 3 Insoluble sulfur 2.5 4 Zinc Oxide 8 5 Cobalt salt (CN20.5%) 1.5 6 B-20-S or Example 1-9 1.5 7 Vulcanization accelerator 1 8 Vulcanizing agent 5 9 Antioxidant RD 0.5 10 Antioxidants 1.5 11 Microcrystalline wax 1 12 Stearic acid 2 13 Methylene acceptor - HMMM (65%) 3.5

[0045] The process of preparing vulcanized rubber is as follows:

[0046] In the first step, rubber components such as natural rubber are added to a mixer at 150°C, preheated and prepared into a masterbatch, followed by adding carbon black and plasticizer in small amounts multiple times, keeping the mixer running to ensure uniform dispersion.

[0047] In the second step, the resorcinol cinnamaldehyde resin and B-20-S prepared in Examples 1-9 were added to an internal mixer at 145° C. to obtain a rubber compound.

[0048] In the third step, the sulfur, accelerator, HMMM, vulcanizer, antioxidant, oxidant, wax, zinc oxide, stearic acid and other composition ingredients in the above table are added to a mixer at 100°C to obtain a modified vulcanized rubber. The product is then placed in a constant temperature and humidity environment for 12 hours, with a constant temperature (25°C) and humidity (50%). Subsequently, its vulcanization, shape, and optimal vulcanization degree are tested at 150°C to evaluate its mechanical properties. The vulcanization and scorch properties of the rubber are as follows:

[0049] Methylene acceptor B-20-S Example 2 B-20-S Example 2 Number of recipients 1.5 1.5 2 2 Methylene donor 2.5 2.5 2.8 2.8 ML 2.03 2.10 2.16 2.24 MH 26.4 27.3 27.7 28.0 TS1 1.21 1.24 1.26 1.24 TS2 1.84 1.91 1.76 1.79 T10 2 1.96 2.04 2.14 T50 4.99 4.95 5.06 5.04 T90 12.4 11.1 12.47 10.9

[0050] From the data in the table, it can be seen that the rubber compound with the resorcinol-cinnamaldehyde resin of the present invention has a faster vulcanization speed than the rubber compound with B-20-S, reaches T90 faster, and the vulcanization speed is increased by 12.0-15.9%. Compared with the traditional resorcinol formaldehyde resin, the resin of the present invention can better promote the vulcanization of rubber.

[0051] Subsequently, the mechanical properties of the obtained rubber compound were tested. The present invention advocates the use of hydroxycinnamaldehyde to replace formaldehyde for reaction. The introduction of double bonds and benzene rings can improve its corresponding mechanical properties, so it is necessary to test its modified rubber. The adhesion with steel cord is tested using the standard ASTM D1871-2004. The vulcanization conditions are 155℃*40min, and the steel cord specifications are: 3+9+15*0.22+1. The tensile properties are tested using the GB / T 528-2009 standard; the hardness is tested using the GB / T531.1-2008 standard. The following table shows the properties of the rubber compound

[0052]

[0053] When producing rubber products, the rubber and reinforcing materials, such as metal steel wire, need to have strong initial adhesion and adhesion after aging to ensure that the rubber products still have excellent application performance and long service life after aging. According to the data in the above table, compared with B-20-S, due to the presence of double bonds and benzene rings, the resin exhibits good mechanical properties, and its steel wire adhesion performance is also slightly improved.

[0054] This implementation mode is only an exemplary description of this patent and does not limit its protection scope. Personnel in this field may also make partial changes to it. As long as it does not exceed the spirit of this patent, it shall be regarded as an equivalent replacement of this patent and shall be within the protection scope of this patent.

Claims

1. A resorcinol-cinnamaldehyde resin, characterized in that: The structure of the resorcinol-cinnamaldehyde resin is as follows: Wherein, R is independently selected from hydrogen, C2-C10 alkyl, aralkyl containing C2-C6 substituents, R1 is an ortho- or para-hydroxyl group, and m is an integer of 1-50.

2. A method for preparing the resorcinol-cinnamaldehyde resin according to claim 1, characterized in that: The following steps are included in sequence: Step S1, heating resorcinol to 90-150° C., then adding an acidic catalyst, stirring evenly, at a speed of 100-200 rpm, and dropping an unsaturated olefin compound to cause an alkylation reaction between resorcinol and the olefin compound; Step S2, adding hydroxycinnamaldehyde compounds and reflux under heat preservation; Step S3, after the reflux is completed, the temperature is raised to 100-180° C. and atmospheric distillation is performed for 30-100 minutes; Step S4, after the atmospheric pressure reflux is completed, a terminator is added, followed by vacuum distillation, the vacuum degree is -0.01 to -0.1 MPa, and the vacuum distillation time is 10 to 90 minutes, to obtain the resorcinol-cinnamaldehyde resin of formula (1).

3. The method for preparing the resorcinol-cinnamaldehyde resin according to claim 2, characterized in that: The hydroxycinnamaldehyde compounds are 2-hydroxycinnamaldehyde and 4-hydroxycinnamaldehyde; the molar ratio of the resorcinol to the hydroxycinnamaldehyde compounds is 1:0.2-0.75, preferably 1:0.45-0.

65.

4. The method for preparing the resorcinol-cinnamaldehyde resin according to claim 2, characterized in that: The unsaturated olefin compound is at least one of styrene, divinylbenzene, p-methylstyrene, vinyltoluene or α-methylstyrene, and the molar ratio of the resorcinol to the unsaturated olefin compound is 1:0.1-0.95, preferably 1:0.35-0.

6.

5. The method for preparing the resorcinol-cinnamaldehyde resin according to claim 2, characterized in that: The acid catalyst includes at least one of an inorganic acid and an organic acid. The inorganic acid includes sulfuric acid, hydrobromic acid, phosphoric acid, and hydrochloric acid. The organic acid includes benzenesulfonic acid, dodecylsulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, phenolsulfonic acid, chlorobenzenesulfonic acid, and sodium sulfonate. The amount of the acid catalyst is 0.1 to 10% of the mass of the resorcinol, preferably 0.5 to 4%.

6. The method for preparing the resorcinol-cinnamaldehyde resin according to claim 2, characterized in that: The terminator is an organic base, an alkali metal or a hydroxide, including at least one of triethylamine, diethylamine, potassium hydroxide, sodium hydroxide and calcium hydroxide. The amount of the terminator is 0.1-8% of the mass of the phenolic compound, preferably 0.5-4%. The phenolic compound includes resorcinol and alkylresorcinol.

7. A modified vulcanized rubber composition, characterized in that: The preparation raw materials include: a rubber component selected from natural rubber or synthetic rubber, a methylene donor, and a methylene acceptor. The methylene acceptor is the resorcinol-cinnamaldehyde resin prepared according to claim 1.

8. The modified vulcanized rubber composition according to claim 7, characterized in that The rubber component is selected from at least one of isobutylene rubber and ethylene-propylene copolymer, polybutadiene, cis-1,4-polyisoprene, acrylonitrile and butadiene copolymer, acrylonitrile and isoprene copolymer, isobutylene rubber, isoprene and butadiene copolymer, and styrene and butadiene copolymer.

9. Use of the modified vulcanized rubber composition according to claim 7, characterized in that: Includes tires, rubber hoses and belts, rubber seals and gaskets, shock absorbers, bridge bearings, flooring materials, roofing and waterproofing materials, conveyor belts, industrial hoses and belts, gloves and medical tubing, aircraft tires, seals and gaskets, diving suits and equipment.

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