阅读说明：本技术 快速固化有机硅改性酚醛树脂的制备方法 (Preparation method of fast-curing organic silicon modified phenolic resin ) 是由 何冬梅 宋佃凤 郁国强 刘娜 汤秀秀 吴立群 于 2020-11-23 设计创作，主要内容包括：本公开涉及一种有机硅酚醛树脂,采用有机硅和尿素作为改性剂,制备的有机硅酚醛树脂能够促进酚醛树脂的快速固化,具有固化时间短,固化温度低,存储时间长,利于后续成型工艺的优势,工艺简单,适用于工业化生产。(The invention relates to an organic silicon phenolic resin, which adopts organic silicon and urea as modifiers, can promote the rapid curing of the phenolic resin, has the advantages of short curing time, low curing temperature, long storage time, contribution to the subsequent forming process, simple process and suitability for industrial production.)

1. A preparation method of a fast curing organic silicon modified phenolic resin is characterized in that organic silicon is used as a modifier, urea is used as an accelerant, and the fast curing organic silicon modified phenolic resin is obtained by emulsification and organic silicon modification.

2. The method of claim 1, wherein the silicone is selected from the group consisting of dodecyltrimethoxysilane, hexadecyltrimethoxysilane, and the like.

3. The process according to claim 1, wherein the mass ratio of urea to silicone is 5-20: 1; the total mass of the organic silicon and the urea accounts for 5-15 wt% of the mass ratio of the raw materials.

4. The preparation method according to claim 1, comprising the following steps: (1) phenolic resin preparation, (2) organosilicon hydrolysis and (3) organosilicon phenolic resin preparation.

5. The method of claim 4, wherein step (1) the phenolic resin is prepared by: weighing phenol, formaldehyde and ammonia water according to the raw material ratio, adding the weighed phenol, formaldehyde and ammonia water into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to obtain a colorless transparent solution, adding urea, heating, emulsifying, and distilling under reduced pressure.

6. The method of claim 4, wherein step (2) comprises hydrolyzing the organosilicon: weighing organic silicon in a beaker, and adding a certain amount of ammonia water and ethanol for hydrolysis.

7. The method of claim 6, wherein step (3) produces a silicone phenolic resin: and (3) adding the organosilicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), and heating to 85-100 ℃ for 20-30 min.

8. The method according to claim 5, wherein the emulsification process of step (1) is: weighing phenol, formaldehyde and ammonia water, adding the phenol, the formaldehyde and the ammonia water into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating, adjusting the temperature rise rate, gradually and slowly raising the temperature to 90-100 ℃, and keeping the temperature for 10-30min to obtain a colorless transparent solution; cooling to 60-80 ℃, adding urea, heating to 90-100 ℃, keeping the temperature for 30-40min, and emulsifying; the solution changed from slightly yellowish to milky to a color which disappeared rapidly, then changed from a clear liquid to milky, and was kept for 20 min.

9. The method according to claim 8, wherein the vacuum distillation in step (1) comprises: vacuum distilling at 80-100 deg.C to obtain clear transparent resin from turbid to light yellow; preferably 80-90 deg.C.

10. An organosilicon-modified phenolic resin obtained by the production method according to any one of claims 1 to 9.

Technical Field

The disclosure belongs to the field of phenolic resin, and relates to a method for modifying phenolic resin by using an organic silicon material.

Background

Phenol resin is a thermosetting resin synthesized from phenol and formaldehyde in the presence of a catalyst, and has excellent mechanical properties, heat resistance, mechanical properties, electrical insulation properties, molding processability, flame retardancy, and the like, as well as high adhesive strength, and the like, and thus is widely used in the fields of composite materials such as automobiles and aerospace, buildings, electronics and the like. However, the method also has the defects of low curing speed, long curing time and the like, so that the production efficiency is low, the energy consumption is high, and the application range of the phenolic resin is limited to a certain extent. Moreover, because the curing temperature of the phenolic resin is high, but methylene and phenolic hydroxyl on the main chain of the phenolic resin are easily oxidized at high temperature to influence the performance of the phenolic resin, if the curing condition of the phenolic resin can be reduced, namely the curing temperature of the phenolic resin is reduced, the curing time is shortened, the content of free phenol and free aldehyde is reduced, the production cost can be reduced, the economic benefit of the product is increased, and the application field of the phenolic resin is expanded.

In order to solve the problems, the prior art generally adopts the modes of increasing the reaction degree of the phenolic resin, adding a metal ion catalyst, modifying by acid and alkali, adding a curing accelerator and the like to reduce the curing time and the curing temperature of the phenolic resin.

The invention patent publication No. CN101067016A discloses "a method for synthesizing and using a fast-curing phenolic resin". The patent is mainly used for preparing impregnating resin for impregnating wood fiber base paper. In the synthesis and use method, divalent metal ions are used as a formula of a catalyst and appropriate process conditions are adopted, and before paper is impregnated, an acidic halogen compound is added as a curing agent to prepare resin. However, ethanol is added at the end of the preparation of the impregnating resin, so that the cost is increased, and the impregnated paper still needs to be cured by hot pressing at 140 ℃.

Chinese patent application publication No. CN1175597A discloses a method for preparing thermosetting phenolic resin, which adopts divalent metal manganese salt as an alkaline catalyst, phosphoric acid and formic acid as an acidic catalyst, and utilizes the acceleration effect of divalent metal manganese ions under the weak acidic condition to accelerate the curing speed of the phenolic resin, wherein the exothermic peak temperature of the obtained phenolic resin is 135 ℃, the gel time at room temperature is 1.5h, and the curing time is 14 h. The phenolic resin produced by the method shows higher curing speed, and simultaneously has the defect of short resin storage period.

The Chinese patent application publication No. CN1916071A discloses a modified thermosetting fast curing phenolic resin, which mainly aims at the defect of long curing time of phenolic resin for glass fiber pre-impregnated cloth for a glass fiber reinforced plastic fishing rod, and the time required for baking and shaping the modified phenolic glass fiber pre-impregnated cloth rolled into the fishing rod is shortened by adding urotropine into an A-stage thermosetting phenolic resin solution, wherein the curing time is shortened from the original 3 hours to 1-2.5 hours. The phenolic resin produced by the method shows higher curing speed, but the method still cannot change the weak points of long curing time and single forming process of the phenolic resin.

The existing preparation method needs to add organic solvent ethanol and the like at the final stage of preparing the impregnating resin, so that the cost is increased, and the impregnated paper still needs to be cured by hot pressing at the temperature of more than 150 ℃. Some phenolic resins show lower curing temperature, but the curing speed needs more than 3h, and the storage period of the resins is too short.

Disclosure of Invention

Aiming at the defects of the prior art, the method for modifying the phenolic resin by the organic silicon is provided, the problems of high curing temperature, long curing time and the like of the conventional phenolic resin can be solved, and the curing cost is reduced.

The organic silicon phenolic resin is prepared by adopting organic silicon as a modifier and urea as an accelerant, and the rapid curing of the phenolic resin is promoted. Specifically, the present disclosure provides a method for preparing a fast curing silicone phenolic resin, comprising the steps of:

(1) preparing phenolic resin: weighing phenol, formaldehyde and ammonia water according to the raw material ratio, adding the weighed phenol, formaldehyde and ammonia water into a three-neck flask with a condenser pipe device, inserting a thermometer, stirring, and heating at 60-80 ℃ to obtain a colorless transparent solution;

regulating the heating rate to gradually and slowly raise the temperature to 90-100 ℃, keeping the temperature for 10-30min, reducing the temperature to 60-80 ℃, adding urea, heating to 90-100 ℃, keeping the temperature for 40min, and emulsifying; the solution changes from light yellow to milky white to color disappearance, then changes from transparent liquid to milky white and keeps for 20 min;

removing the reflux device, maintaining the temperature at 80-100 deg.C, and distilling under reduced pressure to obtain clear and transparent resin from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing organic silicon in a beaker, adding ammonia water and ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 85-100 ℃, and keeping the temperature for 20-30min to obtain the final product which is milk white.

Preferably, the raw materials are mixed according to the following ratio by taking the total amount of the raw materials as a reference: 60-66 wt% of phenol; 24-29 wt% of formaldehyde; ammonia water: 1.5-2 wt%; urea: 7-10 wt%; organosilicon: 0.5-1.2 wt%.

More preferably, the mass ratio of urea to silicone is 5-20:1, preferably 6-16: 1;

more preferably, the total mass of the organosilicon and the urea accounts for 5-15 wt%, preferably 8-12 wt% of the total mass of the raw materials.

Preferably, the organosilicon is selected from dodecyl trimethoxy silane and hexadecyl trimethoxy silane, the organosilicon has a long flexible chain structure, and due to the activity of the organosilicon, silicon hydroxyl generated by hydrolysis can react with phenolic hydroxyl or hydroxymethyl in phenolic resin, wherein Si-OH bonds are formed and then self-polymerization is carried out to form Si-O-Si bonds and block terminal groups.

Under the environment of alkaline catalyst ammonia water, the self-polymerization reaction between p-methylol phenol is promoted, an active group p-methylene bond bridge is formed in the resin, so that the copolymerization reaction of urea and phenolic aldehyde is promoted, and the organic hydrolysate is added to be crosslinked into a three-dimensional network, so that the number of hydroxyl in the resin is reduced, and the curing is promoted. The urea is added in batches and respectively participates in the two stages of addition and polycondensation of the phenolic resin, so that the reaction rate is accelerated, and the free phenol and aldehyde in the resin are reduced. The process of phenolic resin synthesis and step-by-step emulsification is optimized.

More preferably, the present disclosure provides a method for preparing a silicone phenolic resin, which comprises adding phenol in batches, wherein formaldehyde is first added in an excess amount, and in a system in which formaldehyde is first added in an excess amount, on one hand, the number of hydroxyl groups can be controlled, and on the other hand, self-polymerization of silicon hydroxyl groups of a silicone hydrolysate and phenolic hydroxyl groups of a resin is promoted, so that side reactions are reduced, and terminal group self-polymerization is avoided.

And then adding the residual phenol, on one hand, the residual phenol can completely react with the residual formaldehyde to improve the uniformity of the reaction, and on the other hand, the number of phenolic hydroxyl groups and the modification speed of the organic silicon are controlled to effectively reduce free aldehyde in the system and effectively reduce the curing temperature, and the influence on the curing effect caused by one-time excessive addition is avoided.

Specifically, the preparation method is as follows:

preparing phenolic resin: weighing formaldehyde, ammonia water, 1/2 mass phenol and 1/2 urea according to the raw material ratio, adding the formaldehyde, the ammonia water, the 1/2 mass phenol and the 1/2 urea into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 60-80 ℃, and heating to obtain a colorless and transparent solution; regulating the temperature rise rate to gradually and slowly rise the temperature to 90-100 ℃, and keeping the temperature for 20-30 min;

cooling to 60-80 ℃, adding the rest 1/2 mass phenol and 1/2 mass urea, preserving heat for 20-30min, heating to 90-100 ℃, keeping the temperature for 30-40min, and further emulsifying;

wherein the solution is changed from light yellow to milky white until the color disappears rapidly, and then is changed from transparent liquid to milky white and kept for 20 min;

removing the reflux device, maintaining the temperature at 80-100 deg.C, and distilling under reduced pressure to obtain clear and transparent resin from turbid to light yellow;

(2) hydrolyzing organic silicon:

putting organic silicon in a beaker, adding ammonia water and ethanol, and completely hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 85-100 ℃, and keeping the temperature for 20-30min to obtain the final product which is milk white.

The beneficial effect of this disclosure:

1. the organic silicon modified phenolic resin provided by the disclosure improves the curing of the phenolic resin, can be cured quickly, and can be cured at room temperature for 0.5-1h, so that the production period of the product is shortened.

2. According to the organic silicon modified phenolic resin provided by the disclosure, divalent metal ions are not used as a catalyst, so that the process is simplified, the production cost is reduced, and the recovery of waste catalysts is avoided.

3. According to the phenolic resin preparation process, the phenolic resin and the organic silicon hydrolysis process parameters are strictly controlled, the reaction temperature and the reaction time are optimized, reduced pressure distillation is combined, the milky organic silicon phenolic resin is obtained, the purity is high, the side reaction is less, a high-temperature heating device is not needed, the energy is saved, the cost is lower, the resin viscosity is about 400CP, and the storage time is long.

4. The present disclosure also optimizes the internal structure of the silicone phenolic resin by increasing the uniformity of the reaction principle through stepwise mixing, thereby further improving the curing performance.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

FIG. 1 is a schematic diagram of a synthetic process of an organosilicon modified phenolic resin.

Detailed Description

The present disclosure will be described in further detail with reference to the drawings and embodiments. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the present disclosure. It should be further noted that, for the convenience of description, only the portions relevant to the present disclosure are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict. The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Example 1

The raw materials comprise the following components in percentage by mass: 60% of phenol, 29% of formaldehyde, 2% of ammonia water, 8% of urea and 1% of organic silicon;

(1) preparing phenolic resin: weighing 60 parts by weight of phenol, 29 parts by weight of formaldehyde and 2 parts by weight of ammonia water according to the raw material ratio, adding the weighed materials into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

regulating the heating rate to gradually and slowly raise the temperature to 90 ℃, keeping the temperature for 10min, reducing the temperature to 60 ℃, adding 8 parts by weight of urea, raising the temperature to 90 ℃, keeping the temperature for 40min, and emulsifying; the solution changes from light yellow to milky white to color disappearance, then changes from transparent liquid to milky white and keeps for 20 min;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 1 part by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 2 parts by weight of ammonia water and 4 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), keeping the temperature at 85 ℃ for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Example 2

The raw materials comprise the following components in percentage by mass: 62% of phenol, 28% of formaldehyde, 1.5% of ammonia water, 8% of urea and 0.5% of organic silicon;

(1) preparing phenolic resin: weighing 62 parts by weight of phenol, 28 parts by weight of formaldehyde and 1.5 parts by weight of ammonia water according to the raw material ratio, adding the weighed materials into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

reducing the heating rate, adjusting the heating rate to gradually and slowly raise the temperature to 90 ℃, keeping the temperature for 20min, reducing the temperature to 60 ℃, adding 8 parts by weight of urea, raising the temperature to 90 ℃, keeping the temperature for 40min, and emulsifying; wherein the solution is changed from light yellow to milky white until the color disappears rapidly, and then is changed from transparent liquid to milky white and kept for 20 min;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 0.5 part by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 1 part by weight of ammonia water and 2 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(4) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), keeping the temperature at 85 ℃ for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Example 3

The raw materials comprise the following components in percentage by mass: 62% of phenol, 25% of formaldehyde, 2% of ammonia water, 10% of urea and 1% of organic silicon;

(1) preparing phenolic resin: weighing 62 parts by weight of phenol, 25 parts by weight of formaldehyde and 2 parts by weight of ammonia water according to the raw material ratio, adding the weighed materials into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

reducing the heating rate, adjusting the heating rate to gradually and slowly raise the temperature to 100 ℃, keeping the temperature for 20min, reducing the temperature to 80 ℃, adding 10 parts by weight of urea, raising the temperature to 100 ℃, keeping the temperature for 40min, and emulsifying; wherein the solution is changed from light yellow to milky white until the color disappears rapidly, and then is changed from transparent liquid to milky white and kept for 20 min;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 1 part by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 2 parts by weight of ammonia water and 4 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 85 ℃, carrying out modification reaction for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Example 4

The raw materials comprise the following components in percentage by mass: 66% of phenol, 24% of formaldehyde, 1.8% of ammonia water, 7% of urea and 1.2% of organic silicon;

(1) preparing phenolic resin: weighing 66 parts by weight of phenol, 24 parts by weight of formaldehyde and 1.8 parts by weight of ammonia water according to the raw material ratio, adding the weighed materials into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

regulating the heating rate to gradually and slowly raise the temperature to 100 ℃, keeping the temperature for 20min, reducing the temperature to 80 ℃, adding 7 parts by weight of urea, raising the temperature to 100 ℃, keeping the temperature for 40min, and emulsifying; wherein the solution is changed from light yellow to milky white until the color disappears rapidly, and then is changed from transparent liquid to milky white and kept for 20 min;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 1.2 parts by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 2.4 parts by weight of ammonia water and 4.8 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 90 ℃, reacting for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Example 5

The raw materials comprise the following components in percentage by mass: 62% of phenol, 25% of formaldehyde, 2% of ammonia water, 10% of urea and 1% of organic silicon;

(1) preparing phenolic resin: weighing 31 parts by weight of phenol, 25 parts by weight of formaldehyde, 2 parts by weight of ammonia water and 5 parts by weight of urea according to the raw material ratio, adding the weighed materials into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

regulating the heating rate to gradually and slowly raise the temperature to 100 ℃, keeping the temperature for 20min, cooling to 80 ℃, adding the rest 31 parts by weight of phenol and 5 parts by weight of urea, keeping the temperature for 20min, raising the temperature to 100 ℃, keeping the temperature for 40min, and further emulsifying; wherein the solution is changed from light yellow to milky white until the color disappears rapidly, then is changed from transparent liquid to milky white, and is kept for 20min to complete emulsification;

after the reaction is emulsified, removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 1 part by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 2 parts by weight of ammonia water and 4 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 85 ℃, keeping for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Example 6

The raw material ratio is as follows: the raw materials comprise the following components in percentage by mass: 60% of phenol, 29% of formaldehyde, 2% of ammonia water, 7% of urea and 2% of organic silicon;

(1) preparing phenolic resin: weighing 60 parts by weight of phenol, 29 parts by weight of formaldehyde and 2 parts by weight of ammonia water according to the raw material ratio, adding the weighed materials into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

reducing the heating rate, adjusting the heating rate to gradually and slowly raise the temperature to 90 ℃, keeping the temperature for 20min, reducing the temperature to 60 ℃, adding 7 parts by weight of urea, raising the temperature to 90 ℃, keeping the temperature for 40min, and emulsifying; wherein the solution is changed from light yellow to milky white until the color disappears rapidly, and then is changed from transparent liquid to milky white and kept for 20 min;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 2 parts by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 4 parts by weight of ammonia water and 8 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 85 ℃, keeping for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Example 7

The raw materials comprise the following components in percentage by mass: 60% of phenol, 29% of formaldehyde, 2% of ammonia water, 8.6% of urea and 0.4% of organic silicon;

(1) preparing phenolic resin: weighing 60 parts by weight of phenol, 29 parts by weight of formaldehyde and 2 parts by weight of ammonia water according to the raw material ratio, adding the weighed materials into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

regulating the temperature rise rate to gradually and slowly rise to 100 ℃, keeping the temperature for 20min, reducing the temperature to 80 ℃, adding 8.6 parts by weight of urea, raising the temperature to 100 ℃, keeping the temperature for 40min, and emulsifying; wherein the solution is changed from light yellow to milky white until the color disappears rapidly, and then is changed from transparent liquid to milky white and kept for 20 min;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 0.4 part by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 1 part by weight of ammonia water and 2 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 85 ℃, keeping for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Comparative example 1

(1) Preparing phenolic resin: weighing 60 parts by weight of phenol, 29 parts by weight of formaldehyde and 2 parts by weight of ammonia water, adding the mixture into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow;

(2) hydrolyzing organic silicon:

weighing 1 part by weight of organic silicon dodecyl trimethoxy silane in a beaker, adding 2 parts by weight of ammonia water and 4 parts by weight of ethanol, and hydrolyzing at normal temperature and normal pressure;

(3) preparing organic silicon phenolic resin:

and (3) adding the organic silicon hydrolysate obtained in the step (2) into the phenolic resin obtained in the step (1), heating to 85 ℃, keeping for 20min, and finally obtaining the organic silicon phenolic resin in a milk white state.

Comparative example 2

Preparing phenolic resin: weighing 60 parts by weight of phenol, 29 parts by weight of formaldehyde and 2 parts by weight of ammonia water, adding the mixture into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 80 ℃, wherein the solution is colorless and transparent;

regulating the heating rate to gradually and slowly raise the temperature to 90 ℃, keeping the temperature for 10min, reducing the temperature to 60 ℃, adding 8 parts by weight of urea, raising the temperature to 90 ℃, keeping the temperature for 40min, and emulsifying; the solution changes from light yellow to milky white to color disappearance, then changes from transparent liquid to milky white and keeps for 20 min;

removing the reflux device, keeping the temperature at 80 ℃, and distilling under reduced pressure, wherein the resin is clear and transparent from turbid to light yellow; obtaining the phenolic resin.

Comparative example 3

Weighing 60 parts by weight of phenol, 29 parts by weight of formaldehyde and 2 parts by weight of ammonia water, sequentially adding the phenol, the formaldehyde and the ammonia water into a three-neck flask with a condenser tube device, inserting a thermometer, stirring, heating to 40 ℃, adding 0.5 part by weight of 30% NaOH solution, controlling the temperature at 50 ℃, adding divalent metal ion hydroxide, adding 24 parts by weight of formaldehyde, and preserving the temperature at 60 ℃ for 50min to obtain the divalent metal catalyst modified phenolic resin. The spent catalyst needs to be recycled.

The resin curing parameters for the examples and comparative examples are shown in table 1.

TABLE 1

Experimental data show that the organosilicon modified phenolic resin disclosed by the invention is prepared by adopting organosilicon as a modifier and urea as an accelerator, so that the curing temperature of the phenolic resin is remarkably reduced, the curing time is remarkably shortened, the rapid curing can be realized, the process is simplified, and the cost is reduced. In addition, by controlling the proportion of urea and organic silicon, the curing temperature can be optimized, the curing time can be shortened, the storage time of the resin can be prolonged, and the stability is good. The raw materials are added step by step, so that the reaction uniformity and the emulsification efficiency can be improved, and the reaction process is optimized. By adopting the organic silicon modified phenolic resin, the existing metal catalyst preparation process is abandoned, a simpler and more environment-friendly modification process is adopted, the steps of recovering and treating the waste catalyst are saved, and an excellent technical effect is obtained.

The foregoing is illustrative of the best mode for carrying out the present disclosure, but the scope of the present disclosure is not limited thereto, and it will be understood by those skilled in the art that the foregoing is illustrative only and is not intended to limit the scope of the present disclosure. Other variations or modifications may occur to those skilled in the art, based on the foregoing disclosure, and are still within the scope of the present disclosure.

Those skilled in the art will appreciate that elements not described in detail in this disclosure are well within the skill of those skilled in the art.