阅读说明：本技术 一种高强度水基型酚醛树脂及其制备方法 (High-strength water-based phenolic resin and preparation method thereof ) 是由 余海华 江涛 张立刚 严厚磊 于 2021-09-17 设计创作，主要内容包括：本发明涉及一种高强度水基型酚醛树脂及其制备方法,属于酚醛树脂技术领域,该酚醛树脂包括如下重量份原料：苯酚160份,甲醛溶液400份,液碱2.4份,片碱0.5份,三乙胺10份,二甲基乙醇胺5份,N-甲基乙醇胺5份,碳酸钠2份,尿素250份,水190份,添加剂20-40份；本发明中的水基型酚醛树脂是苯酚甲醛在碱性条件下反应生成,特点是无固废物、无废水、无烟气等。本发明的制备过程中加入了添加剂,使酚醛树脂形成了热稳定性较高的杂环结构并提高了树脂的芳香性,降低了树脂在高温下的分解量；阻燃性能得到改善。本发明制得的水基型酚醛树脂,综合性能好、低毒性；该产品游离醛含量低、粘接性能好。(The invention relates to a high-strength water-based phenolic resin and a preparation method thereof, belonging to the technical field of phenolic resins, wherein the phenolic resin comprises the following raw materials in parts by weight: 160 parts of phenol, 400 parts of formaldehyde solution, 2.4 parts of liquid caustic soda, 0.5 part of caustic soda flakes, 10 parts of triethylamine, 5 parts of dimethylethanolamine, 5 parts of N-methylethanolamine, 2 parts of sodium carbonate, 250 parts of urea, 190 parts of water and 20-40 parts of an additive; the water-based phenolic resin is generated by the reaction of phenol formaldehyde under the alkaline condition, and is characterized by no solid waste, no waste water, no smoke and the like. The additive is added in the preparation process, so that the phenolic resin forms a heterocyclic structure with higher thermal stability, the aromaticity of the resin is improved, and the decomposition amount of the resin at high temperature is reduced; the flame retardant properties are improved. The water-based phenolic resin prepared by the invention has good comprehensive performance and low toxicity; the product has low content of free aldehyde and good bonding property.)

1. A high-strength water-based phenolic resin comprises the following raw materials in parts by weight: 160 parts of phenol, 400 parts of formaldehyde solution, 2.4 parts of liquid caustic soda, 0.5 part of caustic soda flakes, 10 parts of triethylamine, 5 parts of dimethylethanolamine, 5 parts of N-methylethanolamine, 2 parts of sodium carbonate, 250 parts of urea and 190 parts of water, and is characterized by further comprising 20-40 parts of an additive; the additive is prepared by the following steps:

under the protection of nitrogen and at the temperature of 0 ℃,4' -diaminodiphenyl ether and N, N-dimethylformamide are mixed, stirred until the mixture is dissolved, added with pyromellitic dianhydride, stirred and reacted for 5 hours, then added with a modifier and a 4A molecular sieve, and continuously stirred and reacted for 2 hours to obtain the additive.

2. The high-strength water-based phenolic resin as claimed in claim 1, wherein the mass fraction of sodium hydroxide in the liquid alkali is 33%; the mass fraction of formaldehyde in the formaldehyde solution was 44%.

3. The high-strength water-based phenolic resin according to claim 1, wherein the molar ratio of 4,4' -diaminodiphenyl ether to pyromellitic dianhydride is 1: 1; the dosage ratio of the 4,4' -diaminodiphenyl ether to the N, N-dimethylformamide is 1 g: 10 mL; the mass ratio of the 4,4' -diaminodiphenyl ether to the modifier is 2: 0.3.

4. the high-strength water-based phenolic resin according to claim 1, wherein the modifier is prepared by the following steps:

step S11, heating vanillin, acetone and anhydrous potassium carbonate for reflux for 1h, then adding chloroethanol, heating for reflux for 12h, cooling to room temperature after the reaction is finished, adding dichloromethane and deionized water, adjusting the pH value of the water phase to 7 by using sodium hydroxide, carrying out pressure concentration on the obtained organic phase, and removing the solvent to obtain an intermediate 1;

step S12, mixing phosphorus oxychloride and dichloromethane, adding the intermediate 1 and triethylamine at 0 ℃, stirring to react for 1h after the addition is finished, then adding a methanol solution of anhydrous methanol and sodium methoxide, and reacting for 5h at 20 ℃ to obtain an intermediate 2;

and step S13, adding the intermediate 2 into toluene, adding anhydrous aluminum trichloride, carrying out heating reflux reaction for 4 hours, washing the obtained organic phase with a hydrochloric acid aqueous solution with the mass fraction of 5% after the reaction is finished, and carrying out reduced pressure concentration to remove the solvent after the washing is finished, thereby obtaining the modifier.

5. The high-strength water-based phenolic resin according to claim 4, wherein the amount ratio of vanillin, acetone, anhydrous potassium carbonate and chlorohydrin in step S11 is 1.5 g: 20mL of: 1.4 g: 0.8 g;

in the step S12, the dosage ratio of phosphorus oxychloride, the intermediate 1, triethylamine and dichloromethane is 3 g: 6 g: 3.8 g: 50 mL; the dosage ratio of the phosphorus oxychloride to the methanol solution of anhydrous methanol and sodium methoxide is 2 g: 25g of: 10 mL; the molar concentration of the methanol solution of sodium methoxide is 0.2 mol/L;

in the step S13, the dosage ratio of the intermediate 2, the toluene and the aluminum trichloride is 3 g: 30mL of: 1.6 g.

6. The method for preparing the high-strength water-based phenolic resin according to claim 1, which comprises the following steps:

firstly, putting phenol, triethylamine, dimethylethanolamine, N-methylethanolamine, an additive and sodium carbonate into a reaction kettle for heating, dropwise adding a formaldehyde solution and liquid caustic soda within 2 hours, and controlling the temperature in the kettle to be 60-65 ℃;

secondly, heating to 75 ℃ within 20min, and keeping the temperature for 240 min; when the emulsion cloud point reaches 65 ℃, sequentially adding caustic soda flakes and urea, keeping the temperature at 55 ℃ before the urea is added, adding water, stirring, reducing the temperature in the kettle to 25 ℃, standing for 1-2h, and discharging to obtain the high-strength water-based phenolic resin.

Technical Field

The invention belongs to the technical field of phenolic resin, and particularly relates to high-strength water-based phenolic resin and a preparation method thereof.

Background

The phenolic resin is prepared by performing addition polycondensation reaction on phenolic compounds (such as phenol, cresol, xylenol, resorcinol, tert-butylphenol, bisphenol A and the like) and aldehyde compounds (such as formaldehyde, acetaldehyde, paraformaldehyde, furfural and the like) under the action of an alkaline or acidic catalyst, and is generally called as phenolic resin. The reaction of phenol with aldehyde is relatively complex, and the rate of addition and polycondensation reactions and products vary depending on the molar ratio of phenol to formaldehyde and the catalyst used.

The phenolic resin has good acid resistance and mechanical property, and is widely applied due to easy acquisition of raw materials and convenient synthesis. The unmodified phenolic resin can generate obvious oxidation phenomenon at the temperature higher than 200 ℃, even can generate pyrolysis and carbonization phenomena along with the further increase of the temperature, and has poor flame retardant property.

Disclosure of Invention

In order to solve the technical problems mentioned in the background art, the invention aims to provide a high-strength water-based phenolic resin and a preparation method thereof.

The purpose of the invention can be realized by the following technical scheme:

a high-strength water-based phenolic resin comprises the following raw materials in parts by weight:

160 parts of phenol, 400 parts of formaldehyde solution, 2.4 parts of liquid caustic soda, 0.5 part of caustic soda flakes, 10 parts of triethylamine, 5 parts of dimethylethanolamine, 5 parts of N-methylethanolamine, 2 parts of sodium carbonate, 250 parts of urea, 190 parts of water and 20-40 parts of an additive.

A preparation method of high-strength water-based phenolic resin comprises the following steps:

firstly, putting phenol, triethylamine, dimethylethanolamine, N-methylethanolamine, an additive and sodium carbonate into a reaction kettle for heating, dropwise adding a formaldehyde solution and liquid caustic soda within 2 hours, and controlling the temperature in the kettle to be 60-65 ℃;

secondly, heating to 75 ℃ in 20m in, and preserving heat for 240 min; when the emulsion cloud point reaches 65 ℃, sequentially adding caustic soda flakes and urea, keeping the temperature at 55 ℃ before the urea is added, adding water, stirring, reducing the temperature in the kettle to 25 ℃, standing for 1-2h, and discharging to obtain the high-strength water-based phenolic resin.

The invention adopts polymerization method for production. Inorganic alkali and organic alkali can be used as alkaline catalysts, formaldehyde is mainly subjected to addition reaction under the condition of the alkaline catalysts, condensation reaction is slower, the generated initial resin is resol resin, and the main reaction process is as follows:

1. addition reaction:

phenol and formaldehyde firstly undergo an addition reaction to produce hydroxymethyl phenol.

2. Condensation reaction:

the methylol phenols are further condensed to form early stage resins or thermosetting phenolic resins, resols, one-step resins.

(1) Reacting phenol with hydroxymethyl phenol to produce bis (hydroxyphenyl methane);

(2) carrying out a reaction between the hydroxymethyl phenols;

(3) phenol or hydroxymethyl is reacted with dimers, polymers or additives.

Further, the mass fraction of sodium hydroxide in the liquid caustic soda is 33%; the mass fraction of formaldehyde in the formaldehyde solution was 44%.

Further, the additive is prepared by the following steps:

under the protection of nitrogen and at the temperature of 0 ℃,4' -diaminodiphenyl ether and N, N-dimethylformamide are mixed, stirred until the mixture is dissolved, added with pyromellitic dianhydride, stirred and reacted for 5 hours, then added with a modifier and a 4A molecular sieve, and continuously stirred and reacted for 2 hours to obtain the additive. The amino group of 4,4' -diaminodiphenyl ether reacts with pyromellitic dianhydride, and the amino groups at the two ends react with aldehyde groups in the modifier after the reaction to prepare the additive.

Further, the molar ratio of the 4,4' -diaminodiphenyl ether to the pyromellitic dianhydride is 1: 1; the dosage ratio of the 4,4' -diaminodiphenyl ether to the N, N-dimethylformamide is 1 g: 10 mL; the mass ratio of the 4,4' -diaminodiphenyl ether to the modifier is 2: 0.3.

further, the modifier is prepared by the following steps:

step S11, heating vanillin, acetone and anhydrous potassium carbonate for reflux for 1h, then adding chloroethanol, heating for reflux for 12h, cooling to room temperature after the reaction is finished, adding dichloromethane and deionized water, adjusting the pH value of the water phase to 7 by using sodium hydroxide, carrying out pressure concentration on the obtained organic phase, and removing the solvent to obtain an intermediate 1; reacting hydroxyl in vanillin with chlorine of chloroethanol to obtain an intermediate 1;

step S12, mixing phosphorus oxychloride and dichloromethane, adding the intermediate 1 and triethylamine at 0 ℃, stirring to react for 1h after the addition is finished, then adding a methanol solution of anhydrous methanol and sodium methoxide, and reacting for 5h at 20 ℃ to obtain an intermediate 2; reacting hydroxyl on the intermediate 1 with phosphorus oxychloride to obtain an intermediate 2;

and step S13, adding the intermediate 2 into toluene, adding anhydrous aluminum trichloride, carrying out heating reflux reaction for 4 hours, washing the obtained organic phase with a hydrochloric acid aqueous solution with the mass fraction of 5% after the reaction is finished, and carrying out reduced pressure concentration to remove the solvent after the washing is finished, thereby obtaining the modifier. Hydrolyzing the methoxyl on the intermediate 2 to obtain a modifier containing hydroxyl; facilitating the subsequent condensation reaction. In addition, aldehyde groups in vanillin still remain in the modifier.

Further, in step S11, the ratio of the vanillin, acetone, anhydrous potassium carbonate and chlorohydrin used is 1.5 g: 20mL of: 1.4 g: 0.8 g;

in the step S12, the dosage ratio of phosphorus oxychloride, the intermediate 1, triethylamine and dichloromethane is 3 g: 6 g: 3.8 g: 50 mL; the dosage ratio of the phosphorus oxychloride to the methanol solution of anhydrous methanol and sodium methoxide is 2 g: 25g of: 10 mL; the molar concentration of the methanol solution of sodium methoxide is 0.2 mol/L;

in the step S13, the dosage ratio of the intermediate 2, the toluene and the aluminum trichloride is 3 g: 30mL of: 1.6 g.

The invention has the beneficial effects that:

the water-based phenolic resin is generated by reacting phenol and formaldehyde under an alkaline condition, and the invention utilizes formaldehyde solution to produce the phenolic resin and is characterized by no solid waste, no waste water, no smoke and the like.

An additive is added in the preparation process, and the main structure of the additive contains an imide structure, so that the thermal stability is improved; the additive contains a phosphate ester structure, namely P-O-C and P ═ O bonds with higher bond energy are introduced into the resin molecules, so that the phenolic resin forms a heterocyclic structure with higher thermal stability, the aromaticity of the resin is improved, and the decomposition amount of the resin at high temperature is reduced; the flame retardant properties are improved.

The water-based phenolic resin prepared by the invention has good comprehensive performance and low toxicity; the product has low free aldehyde content, good adhesive property and low odor.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Preparing a modifier:

step S11, heating vanillin, acetone and anhydrous potassium carbonate for reflux for 1h, then adding chloroethanol, heating for reflux for 12h, cooling to room temperature after the reaction is finished, adding dichloromethane and deionized water, adjusting the pH value of the water phase to 7 by using sodium hydroxide, carrying out pressure concentration on the obtained organic phase, and removing the solvent to obtain an intermediate 1; wherein the dosage ratio of the vanillin to the acetone to the anhydrous potassium carbonate to the chloroethanol is 1.5 g: 20mL of: 1.4 g: 0.8 g;

step S12, mixing phosphorus oxychloride and dichloromethane, adding the intermediate 1 and triethylamine at 0 ℃, stirring to react for 1h after the addition is finished, then adding a methanol solution of anhydrous methanol and sodium methoxide, and reacting for 5h at 20 ℃ to obtain an intermediate 2; wherein the dosage ratio of phosphorus oxychloride, the intermediate 1, triethylamine and dichloromethane is 3 g: 6 g: 3.8 g: 50 mL; the dosage ratio of the phosphorus oxychloride to the methanol solution of anhydrous methanol and sodium methoxide is 2 g: 25g of: 10 mL; the molar concentration of the methanol solution of sodium methoxide is 0.2 mol/L;

step S13, adding the intermediate 2 into toluene, adding anhydrous aluminum trichloride, heating and refluxing for reaction for 4 hours, washing an obtained organic phase with a hydrochloric acid aqueous solution with the mass fraction of 5% after the reaction is finished, and removing the solvent by concentration under reduced pressure after the washing is finished to obtain a modifier; wherein the dosage ratio of the intermediate 2, the toluene and the aluminum trichloride is 3 g: 30mL of: 1.6 g.

Example 2

The preparation of the additive is carried out by the following steps:

under the protection of nitrogen and at the temperature of 0 ℃,4' -diaminodiphenyl ether and N, N-dimethylformamide are mixed, stirred until the mixture is dissolved, added with pyromellitic dianhydride, stirred and reacted for 5 hours, then added with a modifier and a 4A molecular sieve, and continuously stirred and reacted for 2 hours to obtain the additive. Wherein the molar ratio of the 4,4' -diaminodiphenyl ether to the pyromellitic dianhydride is 1: 1; the dosage ratio of the 4,4' -diaminodiphenyl ether to the N, N-dimethylformamide is 1 g: 10 mL; the mass ratio of the 4,4' -diaminodiphenyl ether to the modifier is 2: 0.3; the modifier was prepared as in example 1.

Example 3

A preparation method of high-strength water-based phenolic resin comprises the following steps:

firstly, putting phenol, triethylamine, dimethylethanolamine, N-methylethanolamine, an additive and sodium carbonate into a reaction kettle for heating, dropwise adding a formaldehyde solution and liquid caustic soda within 2 hours, and controlling the temperature in the kettle to be 60 ℃;

secondly, heating to 75 ℃ in 20m in, and preserving heat for 240 min; when the emulsion cloud point reaches 65 ℃, sequentially adding caustic soda flakes and urea, keeping the temperature at 55 ℃ before the urea is added, adding water, stirring, reducing the temperature in the kettle to 25 ℃, standing for 1h, and discharging to obtain the high-strength water-based phenolic resin.

160 parts of phenol, 400 parts of formaldehyde solution, 2.4 parts of liquid caustic soda, 0.5 part of caustic soda flakes, 10 parts of triethylamine, 5 parts of dimethylethanolamine, 5 parts of N-methylethanolamine, 2 parts of sodium carbonate, 250 parts of urea, 190 parts of water and 20 parts of an additive; the additive was prepared as in example 2; the mass fraction of sodium hydroxide in the liquid caustic soda is 33 percent; the mass fraction of formaldehyde in the formaldehyde solution was 44%.

Example 4

A preparation method of high-strength water-based phenolic resin comprises the following steps:

firstly, putting phenol, triethylamine, dimethylethanolamine, N-methylethanolamine, an additive and sodium carbonate into a reaction kettle for heating, dropwise adding a formaldehyde solution and liquid caustic soda within 2 hours, and controlling the temperature in the kettle to be 65 ℃;

secondly, heating to 75 ℃ in 20m in, and preserving heat for 240 min; when the emulsion cloud point reaches 65 ℃, sequentially adding caustic soda flakes and urea, keeping the temperature at 55 ℃ before the urea is added, adding water, stirring, reducing the temperature in the kettle to 25 ℃, standing for 1.5h, and discharging to obtain the high-strength water-based phenolic resin.

160 parts of phenol, 400 parts of formaldehyde solution, 2.4 parts of liquid caustic soda, 0.5 part of caustic soda flakes, 10 parts of triethylamine, 5 parts of dimethylethanolamine, 5 parts of N-methylethanolamine, 2 parts of sodium carbonate, 250 parts of urea, 190 parts of water and 30 parts of an additive; the additive was prepared as in example 2; the mass fraction of sodium hydroxide in the liquid caustic soda is 33 percent; the mass fraction of formaldehyde in the formaldehyde solution was 44%.

Example 5

A preparation method of high-strength water-based phenolic resin comprises the following steps:

firstly, putting phenol, triethylamine, dimethylethanolamine, N-methylethanolamine, an additive and sodium carbonate into a reaction kettle for heating, dropwise adding a formaldehyde solution and liquid caustic soda within 2 hours, and controlling the temperature in the kettle to be 65 ℃;

secondly, heating to 75 ℃ in 20m in, and preserving heat for 240 min; when the emulsion cloud point reaches 65 ℃, sequentially adding caustic soda flakes and urea, keeping the temperature at 55 ℃ before the urea is added, adding water, stirring, reducing the temperature in the kettle to 25 ℃, standing for 2h, and discharging to obtain the high-strength water-based phenolic resin.

160 parts of phenol, 400 parts of formaldehyde solution, 2.4 parts of liquid caustic soda, 0.5 part of caustic soda flakes, 10 parts of triethylamine, 5 parts of dimethylethanolamine, 5 parts of N-methylethanolamine, 2 parts of sodium carbonate, 250 parts of urea, 190 parts of water and 40 parts of an additive; the additive was prepared as in example 2; the mass fraction of sodium hydroxide in the liquid caustic soda is 33 percent; the mass fraction of formaldehyde in the formaldehyde solution was 44%.

Comparative example 1

Compared with the example 4, no additive is added, and the rest raw materials and the preparation process are kept unchanged.

Mixing the water-based phenolic resin samples prepared in examples 3-5 and comparative example 1 with polyethylene glycol, adding oleic acid and dichloromethane, and stirring to obtain a reaction mixture A;

mixing zinc borate, aluminum hydroxide and barium sulfate whiskers, adding the mixture into the mixture A, and uniformly stirring to obtain a reaction mixture B; adding dicyandiamide into the reaction mixture B, stirring to form emulsion thick, and then extruding to obtain a sample to be measured; marking the samples to be detected as a, b, c and d; corresponding to examples 3-5 and comparative example 1.

Wherein the dosage of each substance is as follows: 50 parts of water-based phenolic resin sample, 6 parts of polyethylene glycol, 1.5 parts of oleic acid, 5 parts of dichloromethane, 15 parts of zinc borate, 12 parts of aluminum hydroxide, 5 parts of barium sulfate whisker and 5 parts of water-based dicyandiamide;

and testing the samples a, b, c and d to be tested, wherein the testing standard is as follows: combustion grade GB/T8624-2006; heat distortion temperature GB/T1634.2-2004; flue gas generation index GB/T20284-2006;

the samples to be tested were tested and the test results are shown in table 1 below:

TABLE 1

	Combustion grade	Heat distortion temperature/. degree.C	Index of smoke generation m2/s2、
				Example 3	A	213	25
Example 4	A	215	22
				Example 5	A	212	24
Comparative example 1	A2	180	38

From the above table 1, it can be seen that the phenolic resin product prepared from the water-based phenolic resin prepared by the invention has excellent flame retardant property and good high temperature resistance.

The samples obtained in examples 3 to 5 were subjected to the test, and the test results are shown in Table 2 below;

TABLE 2

The product is water-based phenolic resin with good comprehensive performance and low toxicity, and has low content of free aldehyde and good bonding performance.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.