WO2024011789A1

WO2024011789A1 - Preparation method for phenol phenolic resin and product obtained thereby

Info

Publication number: WO2024011789A1
Application number: PCT/CN2022/129223
Authority: WO
Inventors: 张聪; 何海波; 张善如; 黄帅; 赵立伟
Original assignee: 山东海科创新研究院有限公司
Priority date: 2022-07-15
Filing date: 2022-11-02
Publication date: 2024-01-18
Also published as: CN115124671A; CN115124671B

Abstract

A preparation method for phenol phenolic resin and a product obtained thereby, belonging to the technical field of preparation of phenolic resin. The preparation method for phenol phenolic resin comprises the following steps: 1) mixing phenol, formaldehyde and water to obtain a transparent solution; 2) mixing the transparent solution with an organic acid and a heteropoly acid salt, and carrying out a reaction with stirring to obtain a first reaction solution; 3) mixing the first reaction solution with a heteropoly acid, and carrying out a reaction to obtain phenol formaldehyde resin; and 4) carrying out dehydration and dephenolization treatment on the phenol formaldehyde resin to obtain phenol phenolic resin. The steps 1)-3) are all carried out in a nitrogen atmosphere.

Description

Preparation method of phenol novolac resin and products obtained therefrom

This application claims priority to the Chinese patent application submitted to the China Patent Office on July 15, 2022, with the application number 202210830296.4 and the application title "A preparation method of phenol novolac resin and the resulting product", the entire content of which is incorporated by reference. incorporated in this application.

Technical field

The present application belongs to the technical field of phenolic resin preparation, and in particular relates to a preparation method of phenol-novolac resin and the resulting product.

Background technique

Phenol novolac epoxy resin is a light brown viscous liquid. It is produced by the polycondensation reaction of phenol and formaldehyde in an acidic medium to obtain a novolac resin, which is then polycondensed with excess propylene oxide in the presence of sodium hydroxide. Because the molecular structure contains many epoxy groups and aromatic nuclei, the cured product has a high cross-linking density and excellent heat resistance and chemical resistance. Therefore, it has gained a good reputation in electronic packaging, copper-clad laminates, rubber and other electronic and electrical fields. Wide range of applications.

In terms of the phenolic resin injection molding process, the ideal injection molding compound should have good fluidity in the barrel and the ability to solidify quickly in the mold. Injection plastics with fast curing characteristics can reduce molding time and improve production efficiency. Phenol novolac resin is used as a tackifier and reinforcing resin in rubber compound formulations, but the relatively slow curing speed and relatively high heat production of phenol novolac resin can affect the adhesion of tire cord to rubber. The biggest feature of high-ortho-position phenolic resin is its fast polymerization speed, relatively low softening point, and curing at a lower temperature. Therefore, the characteristics of high ortho phenolic resin exactly meet this requirement.

At present, the preparation of high ortho phenolic resin is mainly carried out in the presence of catalysts (such as divalent metal ions such as calcium, magnesium, zinc, strontium, cadmium, lead and barium oxides, hydroxides or organic acid salts). . However, the catalytic efficiency of this type of divalent metal weak acid salt catalyst is relatively low, and the reaction process is unstable. The resin is prone to gelation during high-temperature dehydration.

Contents of the invention

In order to solve at least one of the above shortcomings in the prior art, one aspect of the embodiments of the present application provides a method for preparing phenol novolac resin, including the following steps:

1) Mix phenol, formaldehyde and water to obtain a transparent solution;

2) Mix the transparent solution with an organic acid and a heteropolyacid salt, and perform a stirring reaction to obtain a first reaction solution;

3) Mix the first reaction solution and the heteropoly acid to react to obtain a phenol formaldehyde resin;

4) The phenol-formaldehyde resin is dehydrated and dephenolized to obtain a phenol-formaldehyde resin;

The steps 1) to 3) are all performed under nitrogen atmosphere.

In some embodiments of the present application, the temperature during mixing in step 1) is 40-60°C; the molar ratio of formaldehyde to phenol is 1: (0.3-0.7); the molar ratio of water to phenol It is 1: (0.5～1.2).

In some embodiments of the present application, the formaldehyde is paraformaldehyde or an aqueous formaldehyde solution.

In some embodiments of the present application, the organic acid is added in batches in step 2), and the organic acid is one or more of oxalic acid, formic acid, acetic acid, butyric acid, benzoic acid and oxalic acid; The added amount of the organic acid is 0.1% to 1.0% of the molar amount of phenol.

In some embodiments of the present application, in step 2), the heteropoly acid salt is added in batches, and the heteropoly acid salt is 1-butyl-3-methylimidazolium phosphotungstic heteropoly acid salt, 1 bromide -Butyl-3-methylimidazolium phosphotungstic heteropoly acid salt, 1-(3-sulfonate)propyl-3-methylimidazolium phosphotungstic heteropoly acid salt, 1-(3-sulfonate)propyl 1-Butyl-3-methylimidazole silicotungstic heteropoly acid salt, 1-butyl-3-methylimidazole silicotungstic heteropoly acid salt, 1-(3-methylimidazole silicotungsten heteropoly acid salt) Sulfonate)propyl-3-methylimidazole silicon tungsten heteropoly salt, 1-(3-sulfonate)propylpyridine silicon tungsten heteropoly salt, 1-butyl-3-methylimidazole phosphomolybdenum Heteropoly acid salt, 1-butyl-3-methylimidazolium phosphomolybdenum heteropoly acid salt, bromide, 1-(3-sulfonate)propyl-3-methylimidazolium phosphomolybdenum heteropoly acid salt, 1- (3-Sulfonate)propylpyridinium phosphomolybdenum heteropoly acid salt, 1-butyl-3-methylimidazole silicomolybdenum heteropoly acid salt, 1-butyl-3-methylimidazole silicomolybdenum heteropoly acid bromide One of acid salt, 1-(3-sulfonate)propyl-3-methylimidazole silicomolybdate heteropoly acid salt, 1-(3-sulfonate)propylpyridine silicomolybdate heteropoly acid salt, or Several; the addition amount of the heteropolyacid salt is 5% to 20% of the molar amount of phenol.

In some embodiments of the present application, the temperature of the stirring reaction in step 2) is 60-100°C, and the time is 1-3 hours.

In some embodiments of the present application, the heteropoly acid is added in batches in step 3), and the heteropoly acid is one or more of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid. ; The addition amount of the heteropolyacid is 0.1% to 1.0% of the molar amount of phenol.

In some embodiments of the present application, the reaction temperature in step 3) is 60-100°C, and the reaction time is 0.5-1.5h.

In some embodiments of the present application, in step 4), high temperature and high pressure are used to dehydrate and remove phenol; the pressure during dehydration is 10-20KPa, and the temperature is 100-140°C; The pressure is 0.1~10Kpa and the temperature is 150~200℃.

Another aspect of the embodiments of the present application also provides a phenol novolac resin prepared by any of the above methods, the ortho position content of the phenol novolac resin is 25% to 95%, and the residual phenol is ≤1000ppm; Gadde Color absorption ≤ 1.

Compared with the existing technology, the advantages and positive effects of this application are:

(1) The preparation method provided by at least one embodiment of the present application has stable reaction, is not easy to produce gel, has high production efficiency, and the prepared phenol novolac resin has low residual phenol and Gardner color and controllable ortho-position content.

(2) The preparation method provided by at least one embodiment of the present application uses organic acids and heteropolyacid salts as catalysts in the early stage of the reaction. The catalytic ability is weak, so that the reaction is moderated and the intense heat generation in the early stage of the reaction is avoided to cross-link the resin; In the middle stage of the reaction, heteropoly acid is used as the catalyst, which has large hydrogen dissociation ability and strong catalytic ability, which can effectively further increase the polycondensation reaction rate, increase the conversion rate and yield of o-cresol, shorten the reaction cycle, and reduce production costs.

(3) The preparation method provided by at least one embodiment of the present application uses a composite of catalyst heteropolyacid salt and organic acid, and under the action of heteroatoms with high activity and obvious positioning effect, through the polycondensation reaction of phenolic aldehyde, different products are prepared. Ortho content of phenol novolac resin.

(4) The phenol novolac resin prepared in at least one embodiment of the present application has controllable ortho-para content, low residual phenol content, and low chroma.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

The embodiments of the present application provide a method for preparing phenol novolac resin, which includes the following steps:

1) Mix phenol, formaldehyde and water to obtain a transparent solution;

The steps 1) to 3) are all performed under nitrogen atmosphere.

In the embodiment of this application, phenol, formaldehyde and water are mixed to obtain a transparent solution. In some embodiments, the molar ratio of formaldehyde to phenol is 1:(0.3~0.7), optionally 1:(0.4~0.6), further optionally 1:0.5. In some embodiments, the molar ratio of water and phenol is 1:(0.5-1.2), optionally 1:1.1. In some embodiments, the mixing temperature is 40-60°C. In some embodiments, the formaldehyde is optionally formaldehyde or paraformaldehyde.

After obtaining a transparent solution, the embodiment of the present application mixes the transparent solution with an organic acid and a heteropolyacid salt, and performs a stirring reaction to obtain a first reaction liquid. In some embodiments, the added amount of the organic acid is 0.1% to 1.0% of the molar amount of phenol, optionally 0.2% to 0.6%, further optionally 0.3% to 0.5%. In some embodiments, the organic acid is one or more of oxalic acid, formic acid, acetic acid, butyric acid, benzoic acid and oxalic acid, optionally one of oxalic acid, benzoic acid and oxalic acid. or more, further optionally oxalic acid. The organic acid is optionally added in batches.

In some embodiments, the addition amount of the heteropolyacid salt is 5% to 20% of the molar amount of phenol, optionally 6% to 15%, further optionally 8% to 10%. In some embodiments, the heteropoly acid salt is 1-butyl-3-methylimidazolium phosphotungstic heteropoly acid salt, bromide 1-butyl-3-methylimidazolium phosphotungstic heteropoly acid salt, 1 -(3-Sulfonate)propyl-3-methylimidazolium phosphorus tungsten heteropoly salt, 1-(3-sulfonate)propylpyridine phosphotungstic heteropoly salt, 1-butyl-3-methyl 1-butyl-3-methylimidazole silicotungstic heteropoly acid salt, 1-butyl-3-methylimidazole silicotungstic heteropoly acid salt, 1-(3-sulfonate)propyl-3-methylimidazole silicotungstic heteropoly acid Salt, 1-(3-sulfonate)propylpyridine silicon tungsten heteropoly salt, 1-butyl-3-methylimidazole phosphomolybdenum heteropoly salt, 1-butyl-3-methylimidazole bromide Phosphomolybdenum heteropoly acid salt, 1-(3-sulfonate)propyl-3-methylimidazole phosphomolybdenum heteropoly acid salt, 1-(3-sulfonate)propylpyridine phosphomolybdate heteropoly acid salt, 1-Butyl-3-methylimidazole silicomolybdenum heteropoly acid salt, 1-butyl-3-methylimidazole silicomolybdenum heteropoly acid salt, 1-(3-sulfonate)propyl-3- One or more of methylimidazole silicon molybdenum heteropoly acid salt and 1-(3-sulfonate)propylpyridine silicon molybdenum heteropoly acid salt, optionally 1-butyl-3-methylimidazole Phosphotungstic heteropoly acid salt, 1-butyl-3-methylimidazolium phosphotungstic heteropoly acid salt, bromide, 1-(3-sulfonate)propyl-3-methylimidazolium phosphotungstic heteropoly acid salt, 1-(3-Sulfonate)propylpyridinium phosphotungstic heteropoly acid salt, further optionally 1-butyl-3-methylimidazolium phosphotungstic heteropoly acid salt. The heteropolyacid salt is optionally added in portions.

In some embodiments, the temperature of the stirring reaction is 60-100°C, and the time is 1-3 hours.

After obtaining the first reaction liquid, the embodiment of the present application mixes the first reaction liquid and the heteropolyacid and performs a reaction to obtain a phenol-formaldehyde resin. In some embodiments, the heteropoly acid is one or more of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid, optionally phosphotungstic acid or silicotungstic acid, further optionally The ground is phosphotungstic acid. In some embodiments, the addition amount of the heteropolyacid is 0.1% to 1.0% of the molar amount of phenol, optionally 0.2% to 0.6%, further optionally 0.3% to 0.5%. The heteropoly acid is optionally added in portions. In some embodiments, the reaction temperature is 60-100°C, optionally 70-90°C; the reaction time is 0.5-1.5h, optionally 0.8-1h.

After obtaining the phenol-formaldehyde resin, in the embodiment of the present application, the phenol-formaldehyde resin is dehydrated and dephenolized to obtain a phenol-formaldehyde resin. In some embodiments, high temperature and high pressure are used to perform dehydration and phenol removal; the pressure during dehydration is optionally 10-20KPa, and further optionally 12-15KPa; the temperature during dehydration is optionally 100-15KPa. 140°C, further optionally 110 to 130°C. The pressure during dephenolization is optionally 0.1-10KPa, further optionally 1-5Mpa; the temperature during dephenolization is optionally 150-200°C, further optionally 170-180°C.

In the embodiments of this application, heteropolyacid salts and organic acids are used as catalysts in combination, and under the action of heteroatoms with high activity and obvious positioning effects, ortho-ocresol aldehydes with different contents are prepared through the polycondensation reaction of phenolic aldehydes. resin. At the same time, a composite of organic acid and heteropolyacid salt is used as a catalyst, which has weak catalytic ability and moderate reaction, which can avoid the severe exotherm in the early stage of the reaction to cross-link the resin. Then, heteropoly acid is selected as a catalyst in the middle stage of the reaction, which has large hydrogen dissociation ability and strong catalytic ability, which can effectively further increase the polycondensation reaction rate and increase the conversion rate and yield of o-cresol. Shorten the reaction cycle and reduce production costs. At the same time, the phenolic phenolic resin prepared by this method has controllable ortho-para content, controllable softening point and low chroma.

In the embodiments of this application, the ortho-para position content of the phenol novolac resin is controlled through the type and addition amount of the heteropoly acid salt. The reaction mechanism for synthesizing the ortho-controllable phenol novolac resin is as follows: by selecting mixed catalysis of the heteropolyacid acid salt and an organic acid. System, the heteropoly acid salt provides a weakly acidic reaction environment, highlighting the difference in the degree of electrophilic substitution of the hydroxyl "OH" at the ortho and para positions on the phenol ring, and selecting heteroatoms with ortho-guiding functions during the synthesis process (such as P , Si, Fe, Co, etc.) and polyatoms (such as Mo, W, V, Nb, Ta, etc.), so that formaldehyde can react preferentially with the ortho position of phenol to form an unstable chelate. By removing a hydroxyl group and heteroatoms and polyatoms, the polycondensation reaction with phenol continues to form ortho-linked and highly active diphenolmethane. At the same time, the type and content of heteroatoms and polyatoms are controlled, and the reaction with formaldehyde continues to form Phenol novolac resins with different ortho positions.

The embodiments of the present application also provide a phenol novolac resin prepared by any of the above methods. The ortho position content of the phenol novolac resin is 25% to 95%, the residual phenol is ≤1000ppm; the Gardner color is ≤ 1.

In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in conjunction with specific examples, but they should not be understood as limiting the protection scope of the present application.

Example 1

S1. Under a nitrogen atmosphere, add phenol, paraformaldehyde and pure water into the reaction kettle at a molar ratio of 0.5:1:1, and stir at 50°C for 60 minutes to obtain a transparent solution;

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 75°C. After stirring and dissolving completely, add acetic acid with a molar mass of phenol 0.3% and 1-butyl-3 with a molar mass of phenol 5% in 4 batches. -Methylimidazole phosphotungstic heteropoly salt catalyst, stir and react for 2 hours after addition;

S3. Under a nitrogen atmosphere, add 0.2% phenol molar mass of phosphotungstic acid to the reaction solution in step 2), and react at 95°C for 1 hour;

S4. After dehydrating the solution obtained in step 3) at 110°C and a pressure of 20KPa, the temperature is raised to 180°C and the pressure is 1KPa to remove phenol to obtain a phenol novolac resin.

Example 2

S1. Under a nitrogen atmosphere, add phenol, paraformaldehyde and pure water into the reaction kettle at a molar ratio of 1.2:1.8:1, and stir at 40°C for 60 minutes to obtain a transparent solution;

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 70°C. After stirring and dissolving completely, add oxalic acid with a molar mass of phenol 0.3% and 1-butyl-3 with a molar mass of phenol 8% in 5 batches. -Methylimidazole phosphotungstic heteropoly salt catalyst, stir and react for 3 hours after addition;

S3. Under a nitrogen atmosphere, add phenol molar mass 0.1% phosphomolybdic acid to the reaction solution in step 2), and react at 85°C for 1.5 hours;

S4. Dehydrate the solution obtained in step 3) at 120°C and a pressure of 15KPa, then raise the temperature to 190°C and remove phenol under a pressure of 10KPa to obtain a phenol novolac resin.

Example 3

S1. Under a nitrogen atmosphere, add phenol, paraformaldehyde and pure water into the reaction kettle according to a molar ratio of 0.65:2:1, and stir at 40°C for 60 minutes to obtain a transparent solution;

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 80°C. After stirring and dissolution, add oxalic acid with a molar mass of 0.7% of phenol and 1-(3 with a molar mass of phenol of 10% in 5 batches. -Sulfonate)propylpyridinium phosphotungstic heteropoly salt catalyst, stir and react for 1 hour after addition;

S3. Under nitrogen atmosphere, add phenol molar mass 0.3% phosphotungstic acid to the reaction solution in step 2), and react at 100°C for 0.5 hours;

S4. After dehydrating the solution obtained in step 3) at 120°C and a pressure of 20KPa, the temperature is raised to 200°C and the pressure is 5KPa to remove phenol to obtain a phenol novolac resin.

Example 4

S1. Under a nitrogen atmosphere, add phenol, paraformaldehyde and pure water into the reaction kettle at a molar ratio of 0.6:0.90:1, and stir at 40°C for 60 minutes to obtain a transparent solution;

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 70°C. After stirring and dissolving completely, add oxalic acid with a molar mass of phenol 0.6% and 1-butyl bromide with a molar mass of phenol 12% in 4 batches. -3-methylimidazole silicon molybdenum heteropoly salt catalyst, stir and react for 2 hours after adding;

S3. Under nitrogen atmosphere, add phenol molar mass 0.3% silicotungstic acid to the reaction solution in step 2), and react at 90°C for 1 hour;

S4. After dehydrating the solution obtained in step 3) at 110°C and a pressure of 10KPa, the temperature is raised to 200°C and the phenol is removed under a pressure of 10KPa to obtain a phenol novolac resin.

Example 5

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 75°C. After stirring and dissolving completely, add acetic acid with a molar mass of phenol 0.3% and 1-butyl-3 with a molar mass of phenol 8% in 4 batches. -Methylimidazole phosphotungstic heteropoly salt catalyst, stir and react for 2 hours after addition;

S3. Under nitrogen atmosphere, add phenol molar mass 0.2% phosphotungstic acid to the reaction solution in step 2), and react at 95°C for 1 hour;

Example 6

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 75°C. After stirring and dissolution, add acetic acid with a molar mass of 0.3% of phenol and 1-butyl-3 with a molar mass of phenol of 12% in 4 batches. -Methylimidazole phosphotungstic heteropoly salt catalyst, stir and react for 2 hours after addition;

S4. After the solution obtained in step 3) is dehydrated under reduced pressure at 110°C and a pressure of 20KPa, the temperature is raised to 180°C and the phenol is removed under reduced pressure at a pressure of 1KPa to obtain a phenol novolac resin.

Comparative example 1

S1. Under a nitrogen atmosphere, add phenol, paraformaldehyde and pure water into the reaction kettle according to a molar ratio of 0.55:0.80:1, and stir at 40°C for 60 minutes to obtain a transparent solution;

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 70°C. After stirring and dissolution, add 0.6% oxalic acid with phenol molar mass in 4 batches. After the addition is completed, stir and react for 3 hours;

S3. Under a nitrogen atmosphere, add 0.5% phenol molar mass of phosphotungstic acid to the reaction solution in step 2), and react at 90°C for 2 hours;

S4. After the solution obtained in step 3) is dehydrated under reduced pressure at 110°C and a pressure of 20KPa, the temperature is raised to 200°C and the phenol is removed under reduced pressure at a pressure of 1KPa to obtain a phenol novolac resin.

Comparative example 2

S1. Under a nitrogen atmosphere, add phenol, paraformaldehyde and pure water into the reaction kettle according to a molar ratio of 0.60:0.90:1, and stir at 50°C for 60 minutes to obtain a transparent solution;

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 70°C. After stirring and dissolution, add acetic acid with phenol molar mass 0.4% in 4 batches. After the addition is completed, stir and react for 5 hours;

S3. Under nitrogen atmosphere, add phenol molar mass 0.8% oxalic acid to the reaction solution in step 2), and react at 85°C for 4 hours;

S4. After the solution obtained in step 3) is dehydrated under reduced pressure at 105°C and a pressure of 20KPa, the temperature is raised to 190°C and the phenol is removed under reduced pressure at a pressure of 1KPa to obtain a phenol novolac resin.

Comparative example 3

S1. Under a nitrogen atmosphere, add phenol, paraformaldehyde and pure water into the reaction kettle at a molar ratio of 0.45:0.76:1, and stir at 50°C for 60 minutes to obtain a transparent solution;

S3. Under nitrogen atmosphere, add phenol molar mass 0.2% oxalic acid to the reaction solution in step 2), and react at 95°C for 1 hour;

S4. After dehydrating the solution obtained in step 3) under reduced pressure at 110°C and a pressure of 20KPa, the temperature was raised to 180°C and the phenol was removed under reduced pressure at a pressure of 10KPa to obtain phenolic resins with different ortho-position contents.

Comparative example 4

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 70°C. After stirring and dissolution, add acetic acid with 0.2% molar mass of phenol in 4 batches. After the addition is completed, stir and react for 5 hours;

Comparative example 5

S2. Under a nitrogen atmosphere, heat the solution in step 1) to 70°C. After stirring and dissolution, add acetic acid with phenol molar mass 0.8% in 4 batches. After the addition is completed, stir and react for 5 hours;

The phenol novolac resins prepared in Examples 1 to 6 and Comparative Examples 1 to 5 were tested according to corresponding testing standards and methods for softening point, ortho-para position content, residual phenol and chromaticity. The specific test results are shown in Table 1.

Table 1 Test results of phenol novolac resin

It can be seen from Table 1 that the phenol novolac resin prepared in Examples 1 to 6 has an ortho ratio of 25-95%, residual phenol ≤ 1000 ppm, chroma ≤ 1, and the softening point meets the design requirements.

Repeat the operation 3 times for Examples 1, 5-6 and Comparative Examples 2, 4-5, and the specific test results are shown in Table 2.

Table 2 Detection of phenol novolac resin

It can be seen from Table 2 that the reaction product of the method provided in the embodiment of the present application is stable, and there is almost no difference in the ortho-para position content in each batch of phenol novolac resin. At the same time, comparing Examples 1 and 5-6, it can be seen that with the increase in the amount of heteropoly acid salt, the ortho-position content in the phenol novolac resin gradually increases, showing regular changes, but does not occur in Comparative Examples 2, 4-5 Regular changes. It can be seen that the technical solution provided by this application can control the ortho-para position in the phenol novolac resin according to the amount of heteropolyacid salt, and then the production can be carried out according to actual product performance requirements. The specific method for controlling the ortho-para position is: using the technical solution provided by this application, first determine the specific reaction raw materials, heteropoly acid salts, heteropoly acids, raw material dosage, specific reaction conditions and processes before preparation, and first conduct a small Batch test, determine the ortho-para content in the obtained phenol phenolic resin, then adjust the amount of heteropoly acid salt according to the ortho-para content in the product, and test again to obtain the phenol phenolic resin with the target ortho-para content. , and then industrial production can be carried out.

Among them: The test methods for ortho-para content, residual phenol, softening point and colorimetry of phenol phenolic resin are as follows:

1. Inspection of ortho-para position content

1.1 Test device

Agilent GC

1.2 Sample

Weigh 0.1-1mg of resin, add about 20g of acetonitrile, record the exact mass of acetonitrile added, cover the lid, shake well, and wait for measurement.

1.3 Test procedures and test results

1) Set the liquid phase conditions: ODS C18 chromatographic column (4.6mmI.D. , the injection volume is 20ul;

2) After the liquid chromatography baseline is stable, inject samples for detection;

3) Calculate based on the peak area in the spectrum, and record the test results in the inspection report.

2. Inspection of phenol content

2.1 Test device

Agilent GC

2.2 Sample

2.3 Test procedures and test results

3) Calculate the peak area of residual phenol, compare it with the internal standard curve, and record the test results in the inspection report.

3. Chroma

3.1 According to standards

The epoxy resin was tested according to GBT12007.1-1989 epoxy resin color determination method.

3.2 Test instruments

1) Nessler colorimetric tube 25ml

2) Analytical balance

3) Volumetric flask 25ml, 100ml

4) Pipette

3.3 Test steps

1) Prepare Gardner color standard solution No. 1-16 according to the standard;

2) Dissolve 4 parts by mass of epoxy resin in 6 parts by mass of acetone;

3) Introduce the prepared solution into the colorimetric tube and compare it with the prepared Gardner color scale. The color is close to the chromaticity.

4) Complete the test report based on the test results.

4. Test of softening point

4.1 According to standards

The epoxy resin was tested according to the GB/T 12007.6-1989 epoxy resin softening point determination method.

4.2 Test instruments

1)Asphalt softening point tester

4.3 Test steps

1) Melt the resin and introduce it into the sample ring so that the resin liquid level is higher than the ring. After cooling, use a heating knife to scrape it flat;

2) Place the sample ring into the asphalt softening point meter, use glycerol as the heating medium, and set the heating rate to 5°C/min until the temperature at which the steel ball falls to the lower bottom plate after the resin softens is the softening point.

3) Complete the test report based on the test results.

The above are only some of the embodiments of the present application. It should be pointed out that those of ordinary skill in the technical field can also make several improvements and modifications without departing from the principles of the present application. These improvements and modifications can also be made. should be regarded as the scope of protection of this application.

Claims

A method for preparing phenol novolac resin, which is characterized in that it includes the following steps:

1) Mix phenol, formaldehyde and water to obtain a transparent solution;

2) Mix the transparent solution with an organic acid and a heteropolyacid salt, and perform a stirring reaction to obtain a first reaction solution;

3) Mix the first reaction solution and the heteropoly acid to react to obtain a phenol formaldehyde resin;

4) The phenol-formaldehyde resin is dehydrated and dephenolized to obtain a phenol-formaldehyde resin;

The steps 1) to 3) are all performed under nitrogen atmosphere.
The preparation method according to claim 1, characterized in that the temperature during mixing in step 1) is 40-60°C; the molar ratio of formaldehyde to phenol is 1: (0.3-0.7); the water The molar ratio to phenol is 1:(0.5~1.2).
The preparation method according to claim 1, characterized in that the formaldehyde is paraformaldehyde or a formaldehyde aqueous solution.
The preparation method according to claim 1, characterized in that in step 2), organic acid is added in batches, and the organic acid is one of oxalic acid, formic acid, acetic acid, butyric acid, benzoic acid and oxalic acid. or more; the added amount of the organic acid is 0.1% to 1.0% of the molar amount of phenol.
The preparation method according to claim 1, characterized in that in step 2), the heteropoly acid salt is added in batches, and the heteropoly acid salt is 1-butyl-3-methylimidazolium phosphotungstic heteropoly acid. Salt, 1-butyl-3-methylimidazolium phosphotungstic heteropoly salt bromide, 1-(3-sulfonate)propyl-3-methylimidazolium phosphotungstic heteropoly salt, 1-(3- Sulfonate) propylpyridinium phosphotungstic heteropoly acid salt, 1-butyl-3-methylimidazole silicotungstic heteropoly acid salt, bromide 1-butyl-3-methylimidazole silicotungsten heteropoly acid salt, 1-(3-sulfonate)propyl-3-methylimidazole silicotungsten heteropoly acid salt, 1-(3-sulfonate)propylpyridine silicotungsten heteropoly acid salt, 1-butyl-3- Methyl imidazole phosphomolybdenum heteropoly salt, 1-butyl-3-methylimidazole phosphomolybdenum heteropoly salt, bromide, 1-(3-sulfonate)propyl-3-methylimidazole phosphomolybdenum heteropoly salt acid salt, 1-(3-sulfonate)propylpyridinium phosphomolybdenum heteropoly acid salt, 1-butyl-3-methylimidazole molybdenum heteropoly acid salt, 1-butyl-3-methyl bromide Imidazole silicomolybdenum heteropoly acid salt, 1-(3-sulfonate)propyl-3-methylimidazole silicomolybdate heteropoly acid salt, 1-(3-sulfonate)propylpyridine silicomolybdate heteropoly acid salt One or more of them; the addition amount of the heteropolyacid salt is 5% to 20% of the molar amount of phenol.
The preparation method according to claim 1, characterized in that the temperature of the stirring reaction in step 2) is 60-100°C, and the time is 1-3 hours.
The preparation method according to claim 1, characterized in that in step 3), heteropoly acid is added in batches, and the heteropoly acid is phosphotungstic acid, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid. One or more kinds; the addition amount of the heteropolyacid is 0.1% to 1.0% of the molar amount of phenol.
The preparation method according to claim 1, characterized in that the reaction temperature in step 3) is 60-100°C and the reaction time is 0.5-1.5h.
The preparation method according to claim 1, characterized in that in step 4), high temperature and high pressure are used to dehydrate and remove phenol; the pressure during dehydration is 10-20KPa, and the temperature is 100-140°C; The pressure during dephenolization is 0.1-10KPa, and the temperature is 150-200°C.
A phenol novolac resin prepared according to the method of any one of claims 1 to 9, characterized in that the ortho position content of the phenol novolac resin is 25 to 95%, and the residual phenol is ≤1000 ppm; Gardner color degree≤1.