A method for synthesizing modified phenolic resin for rubber reinforcement
Through the raw materials and process conditions with specific ratios, the problem of unreacted phenolic monomers in the synthesis of phenolic resins is solved, and a modified phenolic resin with high strength, low odor and simple process is achieved.
Patent Information
- Application Number
- CN202411948397.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-08
AI Technical Summary
During the synthesis of phenolic resins, a large number of unreacted phenolic monomers exist, resulting in a decrease in the resin strength and a large odor, and the existing treatment methods are complex and costly.
The raw materials with a specific ratio (1 mol of phenolic compound, 0.9-1.1 mol of amine compound, 2-2.4 mol of aldehyde compound, 100-500 g of solvent and 1-10 g of catalyst) were reacted at 80-120°C, followed by adding the catalyst and distilling under reduced pressure to obtain a modified phenolic resin with a low free phenol content.
It effectively reduces the free phenol content in the phenolic resin, improves the strength and durability of the resin, while reducing odor, simplifies the process and reduces costs.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of phenolic resin synthesis, and in particular relates to a method for synthesizing modified phenolic resin for rubber reinforcement. Background Art
[0002] As a polymer material with good wear resistance and high temperature resistance, phenolic resin plays an important role in the manufacture of automobile tires. With the continuous development of automobile industry technology and the continuous improvement of tire performance, the performance requirements for phenolic resin are getting higher and higher. Phenolic resin is a high-quality tire rubber with high hardness, high strength, wear resistance, chemical corrosion resistance and high temperature resistance. These characteristics make it an excellent tire reinforcing agent. By adding phenolic resin to rubber, the tensile strength, wear resistance and high temperature resistance of the tire can be enhanced. In addition, phenolic resin can also improve the stiffness and fatigue resistance of the tire. Phenolic resin can also be used as a bonding agent for bonding and repairing tires. It has extremely strong adhesion and can perform excellent bonding and repair work under high temperature and high pressure, which ensures the durability and reliability of the tire.
[0003] As the technology of the automotive industry continues to improve, the performance of tires is getting higher and higher, and the performance requirements for phenolic resins are also getting higher and higher. In tire manufacturing, most phenolic resins are used to strengthen rubber materials, but in recent years, researchers have begun to apply phenolic resins to the design of tire treads to improve tire performance.
[0004] Phenolic resins used as rubber reinforcement are generally linear phenolic resins, which are usually low molecular weight polymers generated by the reaction of formaldehyde and phenol (molar ratio of 0.75~0.85) in an acidic medium. The linear structure of linear phenolic resins gives it solubility (melt) and certain plasticity. General rubber reinforcement phenolic resins mainly include resorcinol-formaldehyde second-stage phenolic resin, tall oil modified phenolic resin and alkylphenol modified phenolic resin. However, during the synthesis of phenolic resins, there will be a large amount of unreacted phenolic monomers (phenol, alkylphenol, etc.), which will cause problems such as reduced resin strength and strong odor. The common treatment method is high temperature and high vacuum distillation, or washing away phenolic monomers with water or organic solvents. The process is complicated and the cost is high.
[0005] Based on this, this application was developed. Summary of the invention
[0006] The purpose of the present invention is to overcome the defects of the prior art and provide a method for synthesizing a modified phenolic resin for rubber reinforcement. The method solves the long-standing technical problem of high free monomers in phenolic resins, and the free phenol content in the synthesized phenolic resin is low. To achieve the above purpose, the present invention adopts the following technical scheme: A modified phenolic resin for rubber reinforcement is prepared from raw materials in the following proportions: 1 mol of a phenolic compound, 0.9-1.1 mol of an amine compound, 2-2.4 mol of an aldehyde compound, 100-500 g of a solvent and 1-10 g of a catalyst.
[0007] A method for synthesizing the modified phenolic resin for rubber reinforcement comprises the following steps: Add 1 mol of phenolic compound, 0.9-1.1 mol of amine compound, 2-2.4 mol of aldehyde compound and 100-500 g of solvent to a reactor (such as a three-necked flask), and then react at 80-120°C for 2-6 hours. After the reaction, add 1-10 g of catalyst, heat to 150-160°C, and distill under reduced pressure until no solution drips out. Then discharge the material, and the yellow to brownish red solid obtained is the modified phenolic resin for rubber reinforcement. The process route of the synthesis method is as follows.
[0008] .
[0009] Specifically, in the present invention, the phenolic compound includes but is not limited to one or a mixture of two or more of phenol, cardanol, cresol, p-tert-butylphenol, octylphenol, allylphenol, etc. The amine compound includes but is not limited to one or a mixture of two or more of aniline, methylamine, ethanolamine, etc.
[0010] Further, in the present invention, the aldehyde compound includes but is not limited to paraformaldehyde or 30-50% formaldehyde aqueous solution, etc. The solvent includes but is not limited to toluene, xylene, dioxane, N,N-dimethylformamide, etc., or a mixture of two or more thereof.
[0011] Further, in the present invention, the catalyst can be one or a mixture of two or more of oxalic acid (30-100%), hydrochloric acid (10-37%), sulfuric acid (10-50%), phosphoric acid (20-85%), phenolic resin, bisphenol F, bisphenol A, etc. Oxalic acid can be added in solid or liquid form. When the oxalic acid concentration is 100%, it means that it is directly added in solid form. In this application, the concentration of the acid refers to the mass percentage.
[0012] The invention provides a modified phenolic resin for rubber reinforcement synthesized by the method.
[0013] The present invention also provides the use of the modified phenolic resin for rubber reinforcement, which comprises adding the modified phenolic resin into a rubber material to prepare a rubber composition.
[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention first synthesizes benzoxazine and then opens the ring to form benzoxazine resin, which has no small molecules such as free phenol, has high strength and low odor; uses alkylphenols such as cardanol, cresol, p-tert-butylphenol, octylphenol and the like, which have good compatibility with rubber components; uses allylphenol, which can produce an addition reaction with rubber; both phenols can make the rubber have high strength and low odor. The method solves the long-standing technical problem of high free monomers in phenolic resin, and the free phenol content in the synthesized phenolic resin is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is the GPC spectrum of the modified phenolic resin prepared in Example 1. DETAILED DESCRIPTION
[0016] The technical solution of the present invention is further described in detail below in conjunction with the embodiments, but the protection scope of the present invention is not limited thereto.
[0017] In the following examples, all the raw materials used are common commercially available products that can be directly purchased.
[0018] Example 1 A method for synthesizing the modified phenolic resin for rubber reinforcement comprises the following steps: In a three-necked flask, add 1 mol of cardanol, 1 mol of aniline, 2 mol of polyformaldehyde, add 200 g of toluene, react at 100 ° C for 4 hours, add 2 g of oxalic acid, change to the reduced pressure distillation mode, raise the temperature to about 155 ° C, turn on the vacuum for reduced pressure distillation, and after reduced pressure distillation until no solution drips out, discharge the material to obtain 420 g of brown-red solid, which is the modified phenolic resin for rubber reinforcement.
[0019] Figure 1 The GPC spectrum of the modified phenolic resin prepared in Example 1 is given. Figure 1 As shown, the resin molecular weight is 2100 and there is no free cardanol (peak time 11.1 min).
[0020] Example 2 A method for synthesizing the modified phenolic resin for rubber reinforcement comprises the following steps: In a three-necked flask, add 1 mol of octylphenol, 1 mol of methylamine (added in the form of 40% methylamine aqueous solution, containing 1 mol of methylamine), 2 mol of formaldehyde aqueous solution (37%), add 100 g of dioxane, react at 90°C for 6 h, add 10 g of phenolic resin (1% free phenol), change to the vacuum distillation mode, raise the temperature to 150°C, turn on the vacuum distillation, and after the vacuum distillation until no solution drips out, discharge the material to obtain 261 g of light brown solid, which is the modified phenolic resin for rubber reinforcement.
[0021] After testing, the modified phenolic resin product prepared in this embodiment has 0.1% free phenol and a resin molecular weight of 2400.
[0022] Example 3 A method for synthesizing the modified phenolic resin for rubber reinforcement comprises the following steps: In a three-necked flask, add 0.9 mol of octylphenol, 0.1 mol of allylphenol, 1 mol of aniline, 2.2 mol of polyformaldehyde, add 300 g of xylene, react at 90 ° C for 4 hours, add 2 g of bisphenol A, change to the reduced pressure distillation mode, raise the temperature to 160 ° C, open the vacuum for reduced pressure distillation, and after reduced pressure distillation until no solution drips out, discharge the material to obtain 330 g of yellow solid, which is the modified phenolic resin for rubber reinforcement.
[0023] After testing, free phenol was not detected in the modified phenolic resin product prepared in this example, and the resin molecular weight was 2200.
[0024] Example 4 A method for synthesizing the modified phenolic resin for rubber reinforcement comprises the following steps: In a three-necked flask, add 0.9 mol of octylphenol, 0.1 mol of phenol, 1 mol of aniline, 2.2 mol of polyformaldehyde, add 400 g of xylene, react at 90°C for 5 h, add 3 g of hydrochloric acid (10%, mass percentage), change to the vacuum distillation mode, raise the temperature to 160°C, open the vacuum distillation, and after the vacuum distillation until no solution drips out, discharge the material to obtain 320 g of yellow solid, which is the modified phenolic resin for rubber reinforcement.
[0025] After testing, free phenol was not detected in the modified phenolic resin product prepared in this example, and the resin molecular weight was 2500.
[0026] Example 5 A method for synthesizing the modified phenolic resin for rubber reinforcement comprises the following steps: In a three-necked flask, add 0.9 mol of cardanol, 0.1 mol of p-tert-butylphenol, 1 mol of ethanolamine, 2.4 mol of polyformaldehyde, add 500 g of N,N-dimethylformamide, react at 120°C for 3 h, add 5 g of sulfuric acid (20%, mass percentage), change to the vacuum distillation mode, heat to 160°C, open the vacuum distillation, and after the vacuum distillation is completed until no solution drips out, discharge the material to obtain 390 g of yellow solid, which is the modified phenolic resin for rubber reinforcement.
[0027] After testing, free phenol was not detected in the modified phenolic resin product prepared in this example, and the resin molecular weight was 2600.
[0028] Comparative Example 1 In a three-necked flask, add 1 mol of phenol, 0.8 mol of formaldehyde aqueous solution (37%), and 1 g of oxalic acid, raise the temperature to 100°C, react for 3 hours, change to the reduced pressure distillation mode, raise the temperature to 160°C, turn on the vacuum for reduced pressure distillation, and after reduced pressure distillation until no solution drips out, discharge the material to obtain 90 g of yellow solid, which is phenolic resin.
[0029] After testing, the phenolic resin product prepared in this comparative example contained 0.5% free phenol and a resin molecular weight of 2200.
[0030] According to the method and requirements of Q / BLC 4813-93, the phenolic resin products obtained in the above-mentioned embodiments and comparative examples were subjected to performance tests such as hardness, tensile strength, and elongation at break. The experimental data are shown in the following table.
[0031] Table 1 Properties of products prepared in different embodiments It can be seen from the above table that compared with Comparative Example 1, the elongation at break of the modified phenolic resin prepared by the method of the present invention is above 110%, which is significantly better than 90% of Comparative Example 1.
[0032] Although the embodiments of the present invention have been shown and described above, and although the present invention is designed for the synthesis of modified phenolic resin for rubber reinforcement, it can be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the above embodiments without departing from the principles and spirit of the present invention, and all of them are considered to be within the scope of protection of the present invention.
Claims
1. A modified phenolic resin for rubber reinforcement, characterized in that: The method is prepared from raw materials with the following proportions: 1 mol of phenolic compound, 0.9-1.1 mol of amine compound, 2-2.4 mol of aldehyde compound, 100-500 g of solvent and 1-10 g of catalyst.
2. The method for synthesizing the modified phenolic resin for rubber reinforcement according to claim 1, characterized in that: Add 1 mol of phenolic compound, 0.9-1.1 mol of amine compound, 2-2.4 mol of aldehyde compound and 100-500 g of solvent into the reactor, and then react at 80-120° C. for 2-6 hours. After the reaction, add 1-10 g of catalyst, raise the temperature to 150-160° C., and distill under reduced pressure until no solution drips out to obtain the product.
3. The method for synthesizing modified phenolic resin for rubber reinforcement as claimed in claim 2, characterized in that: The phenolic compound is one or a mixture of two or more of phenol, cardanol, cresol, p-tert-butylphenol, octylphenol and allylphenol.
4. The method for synthesizing modified phenolic resin for rubber reinforcement as claimed in claim 2, characterized in that: The amine compound is one or a mixture of two or more of aniline, methylamine and ethanolamine.
5. The method for synthesizing modified phenolic resin for rubber reinforcement as claimed in claim 2, characterized in that: The aldehyde compound is paraformaldehyde or a 30-50% formaldehyde aqueous solution.
6. The method for synthesizing modified phenolic resin for rubber reinforcement as claimed in claim 2, characterized in that: The solvent is one of toluene, xylene, dioxane, N,N-dimethylformamide or a mixture of two or more thereof.
7. The method for synthesizing modified phenolic resin for rubber reinforcement as claimed in claim 2, characterized in that: The catalyst is one of oxalic acid, hydrochloric acid, sulfuric acid, phosphoric acid, phenolic resin, bisphenol F, bisphenol A, or a mixture of two or more thereof.
8. A modified phenolic resin for rubber reinforcement synthesized by the method according to any one of claims 2 to 7.
9. The use of the modified phenolic resin for rubber reinforcement according to claim 1 or 8, characterized in that: The modified phenolic resin is added into a rubber compound to prepare a rubber composition.