A preparation method of sulfomethylphenolic resin

Abstract

The present invention belongs to the technical field of oil drilling fluid treatment agents, and specifically relates to a method for preparing a sulfomethylphenol-formaldehyde resin. The method uses sodium sulfite as a catalyst, which can be hydrolyzed into sodium hydroxide and sodium bisulfite. This method can maintain a stable pH value of the sulfonation reaction system during the sulfonation process, thereby maintaining stable product quality. Furthermore, by adjusting the ratio of the raw materials and regulating the polymerization reaction progress and product viscosity by adding water in batches during the polymerization reaction, the prepared sulfomethylphenol-formaldehyde resin has both good high temperature resistance and saturated salt resistance, and excellent fluid loss reduction effect, meeting the requirements of sulfonated phenol-formaldehyde resin type I and sulfonated phenol-formaldehyde resin type II in Sinopec Enterprise Standard Q / SH0042-2007.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum drilling fluid treating agents, and particularly relates to a preparation method of sulfomethylphenolic resin. Background Art

[0002] With the development of oil drilling, modern oil extraction is increasingly moving towards deep and ultra-deep wells. The deeper the well, the higher the bottomhole temperature, which places higher demands on drilling fluid treatment agents. Fluid loss reducers are a key component of drilling fluid. Currently, the high-temperature resistant fluid loss reducers used on-site are primarily trisulfonic systems, with sulfomethylphenolic resin as a key component. There are two types of sulfomethylphenolic resin commonly used on the market: sulfomethylphenolic resin type I and sulfomethylphenolic resin type II. Type I sulfomethylphenolic resin exhibits high-temperature and salt resistance, but its salt tolerance is only effective at salt concentrations of approximately 15% and is not resistant to saturated salts. Type II sulfomethylphenolic resin exhibits high-temperature and saturated salt resistance, but its fluid loss reduction effect is poor at lower salt concentrations, which can have a certain impact on actual field use. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a method for preparing a sulfomethylphenolic resin. The sulfomethylphenolic resin prepared by the method has good high temperature resistance and saturated salt resistance, and has excellent fluid loss reduction effect, meeting the requirements of sulfonated phenolic resin type I and sulfonated phenolic resin type II in Sinopec enterprise standard Q / SH 0042-2007.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing a sulfomethylphenol-formaldehyde resin, comprising the following steps:

[0006] mixing phenol, a sulfonating agent and a catalyst to carry out a sulfonation reaction to obtain a sulfonated product;

[0007] The mass ratio of the phenol to the sulfonating agent is 6-7:3.2-3.6;

[0008] The catalyst is sodium sulfite; the mass ratio of phenol to catalyst is 6-7:3.2-3.6;

[0009] mixing the sulfonated product with formaldehyde and performing a polymerization reaction to obtain a sulfomethylphenol-formaldehyde resin;

[0010] The amount of the sulfonated product is calculated based on the phenol participating in the sulfonation reaction, and the mass ratio of the phenol to formaldehyde is 6-7:10-14;

[0011] The polymerization reaction comprises sequentially performing a first polymerization reaction and a second polymerization reaction; and adding water in portions during the second polymerization reaction.

[0012] Preferably, the sulfonating agent comprises sodium bisulfite and / or sodium metabisulfite.

[0013] Preferably, the sulfonation reaction temperature is 70-80° C., and the time is 0.5-1.5 h.

[0014] Preferably, the temperature of the first polymerization reaction is 85-95°C.

[0015] Preferably, the viscosity of the reaction product obtained from the first polymerization reaction is 150 to 180 mPa·s.

[0016] Preferably, the second polymerization reaction comprises:

[0017] adding water to the product of the first polymerization reaction to perform a first intermediate polymerization reaction to obtain a first intermediate polymerization product;

[0018] adding water to the first intermediate polymer product for a second time to carry out a second intermediate polymerization reaction to obtain a second intermediate polymer product;

[0019] Water is added to the second intermediate polymerization product for a third time to carry out a third intermediate polymerization reaction.

[0020] Preferably, the temperature of the first intermediate polymerization reaction is 85-95° C.; the time of the first intermediate polymerization reaction is 1-1.5 hours.

[0021] Preferably, the temperature of the second intermediate polymerization reaction is 85-95° C.; and the time of the second intermediate polymerization reaction is 1-1.5 h.

[0022] Preferably, the temperature of the third intermediate polymerization reaction is 95 to 105° C.; and the time of the third intermediate polymerization reaction is 1 to 2 hours.

[0023] Preferably, the mixing of the sulfonated product and formaldehyde is performed by dropwise adding the formaldehyde into the sulfonated product; the dropwise addition speed of the formaldehyde is 13-15 kg / min.

[0024] The invention provides a preparation method of a sulfomethylphenol-formaldehyde resin. The method comprises the following steps: mixing phenol, a sulfonating agent and a catalyst, performing a sulfonation reaction, and obtaining a sulfonation product; the mass ratio of the phenol to the sulfonating agent is 6-7:3.2-3.6; the catalyst is sodium sulfite; the mass ratio of the phenol to the catalyst is 6-7:3.2-3.6; mixing the sulfonation product and formaldehyde, performing a polymerization reaction, and obtaining the sulfomethylphenol-formaldehyde resin; the amount of the sulfonation product is calculated based on the phenol participating in the sulfonation reaction, and the mass ratio of the phenol to the formaldehyde is 6-7:10-14; the polymerization reaction comprises sequentially performing a first polymerization reaction and a second polymerization reaction; and water is added in portions during the second polymerization reaction. The present invention adopts sodium sulfite as a catalyst. Sodium sulfite can be hydrolyzed into sodium hydroxide and sodium bisulfite. This is a reversible reaction. The pH value of the sulfonation reaction system can be kept stable during the sulfonation process, and the product quality will not be affected by the drastic change of the pH value during the sulfonation process. The sodium bisulfite generated after the sodium sulfite is hydrolyzed can also be used as a sulfonating agent to participate in the reaction. By adjusting the ratio of the raw materials and adjusting the polymerization reaction progress and product viscosity by adding water in batches during the polymerization reaction, the prepared sulfomethylphenol-formaldehyde resin has good high temperature resistance and saturated salt resistance and excellent fluid loss reduction effect, and meets the requirements of sulfonated phenol-formaldehyde resin type I and sulfonated phenol-formaldehyde resin type II in Sinopec enterprise standard Q / SH 0042-2007 and the requirements of "Petroleum and Natural Gas Industry Standard of the People's Republic of China - Fluid Loss Reducer for Drilling Fluid - Sulfomethylphenol-formaldehyde Resin SMP" (SY / T5094-2017). DETAILED DESCRIPTION

[0025] The present invention provides a method for preparing a sulfomethylphenol-formaldehyde resin, comprising the following steps:

[0026] mixing phenol, a sulfonating agent and a catalyst to carry out a sulfonation reaction to obtain a sulfonated product;

[0027] The mass ratio of the phenol to the sulfonating agent is 6-7:3.2-3.6;

[0028] The catalyst is sodium sulfite; the mass ratio of phenol to catalyst is 6-7:3.2-3.6;

[0029] mixing the sulfonated product with formaldehyde and performing a polymerization reaction to obtain a sulfomethylphenol-formaldehyde resin;

[0030] The amount of the sulfonated product is calculated based on the phenol participating in the sulfonation reaction, and the mass ratio of the phenol to formaldehyde is 6-7:10-14;

[0031] The polymerization reaction comprises sequentially performing a first polymerization reaction and a second polymerization reaction; and adding water in portions during the second polymerization reaction.

[0032] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art can be used.

[0033] The present invention mixes phenol, a sulfonating agent and a catalyst to carry out a sulfonation reaction to obtain a sulfonated product.

[0034] In the present invention, the sulfonating agent preferably includes sodium bisulfite and / or sodium metabisulfite, more preferably sodium bisulfite. When the sulfonating agent is sodium bisulfite and sodium metabisulfite, the present invention has no particular limitation on the ratio of sodium bisulfite and sodium metabisulfite, and any ratio may be used.

[0035] In the present invention, the mass ratio of the phenol to the sulfonating agent is 6-7:3.2-3.6, preferably 6-6.5:3.2-3.4.

[0036] In the present invention, the catalyst is sodium sulfite; the mass ratio of the phenol to the catalyst is 6-7:3.2-3.6, preferably 6-6.5:3.2-3.4.

[0037] The present invention adopts sodium sulfite as a catalyst. Sodium sulfite can be hydrolyzed into sodium hydroxide and sodium bisulfite. This is a reversible reaction. The pH value of the sulfonation reaction system can be kept stable during the sulfonation process, and the product quality will not be affected by drastic changes in the pH value during the sulfonation process. Sodium bisulfite generated after the hydrolysis of sodium sulfite can also be used as a sulfonating agent to participate in the reaction.

[0038] The ratio of the sulfonating agent to the catalyst in the present invention is high, the reaction speed is relatively moderate, and the ratio of the sulfonating agent is high and the price is cheap, so the cost of the obtained sulfomethylphenolic resin product is relatively low.

[0039] In the present invention, the mixing of phenol, sulfonating agent and catalyst is preferably performed by melting phenol and then adding the sulfonating agent and catalyst while stirring; the stirring rate is preferably 290-310 rpm, more preferably 300 rpm; the stirring temperature is preferably 60-70°C, more preferably 65°C.

[0040] In the present invention, the temperature of the sulfonation reaction is preferably 70-80°C, more preferably 75°C, and the holding time of the sulfonation reaction is preferably 0.5-1.5h, more preferably 1h; the equipment used for the sulfonation reaction is preferably a reactor with a stirrer; the sulfonation reaction is preferably carried out under stirring; the stirring rate is preferably 290-310rpm, more preferably 300rpm.

[0041] After obtaining the sulfonated product, the present invention mixes the sulfonated product with formaldehyde to carry out a polymerization reaction to obtain a liquid sulfonated methylphenolic resin.

[0042] In the present invention, the amount of the sulfonated product is calculated based on the phenol participating in the sulfonation reaction, and the mass ratio of the phenol to formaldehyde is 6-7:10-14, preferably 6-6.5:10-12.

[0043] In the present invention, the sulfonated product and formaldehyde are preferably mixed by adding the formaldehyde dropwise to the sulfonated product; the formaldehyde addition rate is preferably 13 to 15 kg / min, more preferably 13 to 14 kg / min; the sulfonated product and formaldehyde are preferably mixed under stirring; the stirring rate is preferably 290 to 310 rpm, more preferably 300 rpm.

[0044] In the present invention, formaldehyde is added dropwise, which can slow down the polymerization reaction speed, facilitate the control of the temperature of the polymerization reaction system, and prevent implosion.

[0045] In the present invention, the polymerization reaction includes sequentially performing a first polymerization reaction and a second polymerization reaction; water is added in portions during the second polymerization reaction.

[0046] In the present invention, the temperature of the first polymerization reaction is preferably 85-95°C, more preferably 90°C; when the product obtained by the first polymerization reaction turns reddish brown and can be drawn into a wire, the present invention preferably stops the first polymerization reaction; the viscosity of the reaction product obtained by the first polymerization reaction is preferably 150-180mPa·s, more preferably 160-170mPa·s.

[0047] In the present invention, the process of the second polymerization reaction preferably includes:

[0048] adding water to the product of the first polymerization reaction to perform a first intermediate polymerization reaction to obtain a first intermediate polymerization product;

[0049] adding water to the first intermediate polymer product for a second time to carry out a second intermediate polymerization reaction to obtain a second intermediate polymer product;

[0050] Water is added to the second intermediate polymerization product for a third time to carry out a third intermediate polymerization reaction.

[0051] In the present invention, the temperature of the first intermediate polymerization reaction is preferably 85-95°C, more preferably 90°C; the time of the first intermediate polymerization reaction is preferably 1-1.5h, more preferably 1h; the mass ratio of the first added water to the formaldehyde is preferably 3:10-14, more preferably 3:10-12.

[0052] In the present invention, the temperature of the second intermediate polymerization reaction is preferably 85-95°C, more preferably 90°C; the time of the second intermediate polymerization reaction is preferably 1-1.5h, more preferably 1h; the mass ratio of the second added water to the formaldehyde is preferably 5:10-14, more preferably 5:10-12.

[0053] In the present invention, the temperature of the third intermediate polymerization reaction is preferably 95-105°C, more preferably 100°C; the time of the third intermediate polymerization reaction is preferably 1-2h, more preferably 2h; the mass ratio of the third water addition to the formaldehyde is preferably 7:10-14, more preferably 7:10-12.

[0054] In the present invention, the viscosity of the product obtained by the polymerization reaction at 25° C. is preferably 20 to 50 mPa·s, more preferably 30 to 35 mPa·s.

[0055] The present invention adds water during the polymerization reaction, thereby inhibiting polymerization, cooling the reaction, and diluting the reaction mixture. Water is added three times in increments, and this method of adding water can better control the polymerization reaction rate, resulting in a narrow molecular weight distribution of the obtained sulfomethylphenol-formaldehyde resin, thereby obtaining a sulfomethylphenol-formaldehyde resin with stable quality.

[0056] After obtaining the liquid sulfomethylphenol-formaldehyde resin, the present invention preferably further comprises sequentially cooling and drying the liquid sulfomethylphenol-formaldehyde resin to obtain a powdery sulfomethylphenol-formaldehyde resin.

[0057] In the present invention, the cooling is preferably natural cooling; after the cooling, the temperature of the sulfomethylphenolic resin liquid product is preferably less than 40° C.; and the drying equipment is preferably a spray drying tower.

[0058] In the present invention, the molecular weight of the sulfomethylphenolic resin is preferably 8,000 to 10,000, more preferably 9,000.

[0059] In the present invention, the dry basis content of the sulfomethylphenolic resin is preferably ≥90%, more preferably 94-96%, the content of water-insoluble matter is preferably ≤8%, more preferably 3-4%; the cloud point salinity is preferably ≥160 g / L, more preferably 170-185 g / L; the apparent viscosity is preferably ≤25 mPa·s, more preferably 15-20 mPa·s; and the high-temperature and high-pressure fluid loss is preferably ≤20 mL, more preferably 15-16 mL.

[0060] The sulfonated methylphenolic resin prepared by the invention has good high temperature resistance and saturated salt resistance, and excellent fluid loss reduction effect, and meets the requirements of sulfonated phenolic resin type I and sulfonated phenolic resin type II in the Sinopec enterprise standard Q / SH 0042-2007.

[0061] The preparation method of the sulfomethylphenolic resin provided by the invention is simple and easy, has stable product quality, wide adaptability and low cost, and can reduce the raw material and product inventory.

[0062] The technical solutions of the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention, but they should not be understood as limiting the scope of protection of the present invention.

[0063] Example 1

[0064] 700 kg of phenol was melted and pumped into a reactor. The stirrer was started and heated to 60° C., and 320 kg of sodium bisulfite and 320 kg of sodium sulfite were added while stirring at 300 rpm. The temperature was maintained at 70° C. and a sulfonation reaction was carried out for 1 hour to obtain a sulfonated product. 1200 kg of formaldehyde was added dropwise to the sulfonated product at a rate of 13 kg / min while stirring at 300 rpm. After the addition was completed, the temperature was raised to 90° C. and a first polymerization reaction was carried out until the obtained reaction product turned reddish brown and could be drawn into a thread (viscosity was 0.05). The reaction was stopped at 150 mPa·s, 300 kg of tap water was added, and a first intermediate polymerization reaction was carried out for 1 hour. Then, 500 kg of tap water was added, and a second intermediate polymerization reaction was carried out for 1 hour. Then, 700 kg of tap water was added, the temperature was raised to 100° C., and a third intermediate polymerization reaction was continued for 2 hours until the viscosity of the finished product in the reactor at 25° C. was between 20 and 50 mPa·s, thereby obtaining a sulfomethylphenol-formaldehyde resin liquid product; the temperature was naturally lowered to below 40° C., and then dried in a spray drying tower to obtain a sulfomethylphenol-formaldehyde resin powder product.

[0065] Example 2

[0066] 600 kg of phenol was melted and pumped into the reactor. The stirrer was started and heated to 65°C. 340 kg of sodium bisulfite and 340 kg of sodium sulfite were added while stirring at 300 rpm. The temperature was maintained at 75°C and the sulfonation reaction was carried out for 1 hour to obtain a sulfonated product. 1400 kg of formaldehyde was added dropwise at a rate of 15 kg / min while stirring the sulfonated product at 300 rpm. After the addition was completed, the temperature was raised to 90°C and a first polymerization reaction was carried out until the obtained reaction product turned reddish brown and could be drawn into a thread (viscosity of 16 The reaction was stopped when the viscosity of the finished product in the reactor was between 20 and 50 mPa·s at 25° C., and the sulfomethyl phenolic resin liquid product was obtained. The temperature was naturally cooled to below 40° C., and then dried in a spray drying tower to obtain a sulfomethyl phenolic resin powder product.

[0067] Example 3

[0068] 650 kg of phenol was melted and pumped into the reactor. The stirrer was started and heated to 70°C. 360 kg of sodium bisulfite and 360 kg of sodium sulfite were added while stirring at 300 rpm. The temperature was maintained at 80°C and the sulfonation reaction was carried out for 1 hour to obtain a sulfonated product. 1000 kg of formaldehyde was added dropwise to the sulfonated product at a rate of 14 kg / min while stirring at 300 rpm. After the addition was completed, the temperature was raised to 90°C and a first polymerization reaction was carried out until the obtained reaction product turned reddish brown and could be drawn into a thread (viscosity was 0.05). 170 mPa·s), adding 300 kg of tap water, carrying out a first intermediate polymerization reaction for 1 hour, then adding 500 kg of tap water, carrying out a second intermediate polymerization reaction for 1 hour, then adding 700 kg of tap water, raising the temperature to 100° C., and continuing the third intermediate polymerization reaction for 2 hours, so that the viscosity of the finished product in the reactor at 25° C. is between 20 and 50 mPa·s, thereby obtaining a sulfomethylphenol-formaldehyde resin liquid product, naturally cooling to below 40° C., and then drying in a spray drying tower to obtain a sulfomethylphenol-formaldehyde resin powder product.

[0069] Comparative Example 1

[0070] After 700 kg of phenol was melted, it was pumped into the reactor, and the stirrer was started. After heating to 60 ° C, 200 kg of sodium bisulfite and 200 kg of sodium sulfite were added while stirring at 300 rpm. The temperature was maintained at 70 ° C and the sulfonation reaction was carried out for 1 hour to obtain a sulfonated product. 1200 kg of formaldehyde was added dropwise at a rate of 13 kg / min while stirring the sulfonated product at 300 rpm. After the addition was completed, the temperature was raised to 90 ° C and a polymerization reaction was carried out until the obtained reaction product turned reddish brown and could be drawn into a wire. When the temperature is 500° C. (viscosity is 150 mPa·s), 300 kg of tap water is added, and the polymerization reaction is carried out for 1 hour. Then, 500 kg of tap water is added, and the polymerization reaction is carried out again for 1 hour. Then, 700 kg of tap water is added, the temperature is raised to 100° C., and the polymerization reaction is continued for 2 hours, so that the viscosity of the finished product in the reactor at 25° C. is between 20 and 50 mPa·s, thereby obtaining a sulfomethylphenol-formaldehyde resin liquid product. The temperature is naturally reduced to below 40° C., and then dried in a spray drying tower to obtain a sulfomethylphenol-formaldehyde resin powder product.

[0071] Comparative Example 2

[0072] After 700 kg of phenol was melted, it was pumped into the reactor, and the stirrer was started. After heating to 65 ° C, 400 kg of sodium bisulfite and 400 kg of sodium sulfite were added while stirring at 300 rpm. The temperature was maintained at 75 ° C and the sulfonation reaction was carried out for 1 hour to obtain a sulfonated product. 1200 kg of formaldehyde was added dropwise at a rate of 13 kg / min while stirring the sulfonated product at 300 rpm. After the addition was completed, the temperature was raised to 90 ° C and a polymerization reaction was carried out until the obtained reaction product turned reddish brown and could be drawn into a wire. When the temperature is 500° C. (viscosity is 160 mPa·s), 300 kg of tap water is added, and the polymerization reaction is carried out for 1 hour. Then, 500 kg of tap water is added, and the polymerization reaction is carried out again for 1 hour. Then, 700 kg of tap water is added, the temperature is raised to 100° C., and the polymerization reaction is continued for 2 hours, so that the viscosity of the finished product in the reactor at 25° C. is between 20 and 50 mPa·s, thereby obtaining a sulfomethylphenol-formaldehyde resin liquid product. The temperature is naturally reduced to below 40° C., and then dried in a spray drying tower to obtain a sulfomethylphenol-formaldehyde resin powder product.

[0073] Comparative Example 3

[0074] After 700 kg of phenol was melted, it was pumped into the reactor, and the stirrer was started. After heating to 70 ° C, 300 kg of sodium bisulfite and 300 kg of sodium sulfite were added while stirring at 300 rpm. The temperature was maintained at 80 ° C and the sulfonation reaction was carried out for 1 hour to obtain a sulfonated product. 1200 kg of formaldehyde was added dropwise at a rate of 40 kg / min while stirring the sulfonated product at 300 rpm. After the addition was completed, the temperature was raised to 90 ° C and a polymerization reaction was carried out until the obtained reaction product turned reddish brown and could be drawn into a wire. When the temperature is 500° C. (viscosity is 170 mPa·s), 300 kg of tap water is added, and the polymerization reaction is carried out for 1 hour. Then, 500 kg of tap water is added, and the polymerization reaction is carried out again for 1 hour. Then, 700 kg of tap water is added, the temperature is raised to 100° C., and the polymerization reaction is continued for 2 hours, so that the viscosity of the finished product in the reactor at 25° C. is between 20 and 50 mPa·s, thereby obtaining a sulfomethylphenol-formaldehyde resin liquid product. The temperature is naturally reduced to below 40° C., and then dried in a spray drying tower to obtain a sulfomethylphenol-formaldehyde resin powder product.

[0075] Comparative Example 4

[0076] 700 kg of phenol was melted and pumped into a reactor. The stirrer was started and heated to 70° C., and then 300 kg of sodium bisulfite and 300 kg of sodium sulfite were added while stirring at 300 rpm. The temperature was maintained at 80° C. and a sulfonation reaction was carried out for 1 hour to obtain a sulfonated product. 1200 kg of formaldehyde was added dropwise to the sulfonated product at a rate of 13 kg / min while stirring at 300 rpm. After the addition was complete, the temperature was raised to 90° C. and a polymerization reaction was carried out until the obtained reaction product became reddish brown and could be drawn into a thread (viscosity of 170 mPa·s). 600 kg of tap water was added and the polymerization reaction was carried out for another 1 hour. Then, 900 kg of tap water was added and the temperature was raised to 100° C. and the polymerization reaction was continued for 2 hours until the viscosity of the finished product in the reactor at 25° C. was between 20 and 50 mPa·s, thereby obtaining a sulfomethylphenol-formaldehyde resin liquid product. The temperature was naturally lowered to below 40° C. and then dried in a spray drying tower to obtain a sulfomethylphenol-formaldehyde resin powder product.

[0077] Performance Testing

[0078] According to the Sinopec Enterprise Standard Q / SH 0042-2007, the sulfomethylphenolic resins obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were tested indoors as sulfonated phenolic resin type I and sulfonated phenolic resin type II. The results are shown in Tables 1 and 2, respectively.

[0079] Table 1 Detection of sulfonated phenolic resin type I

[0080]

[0081]

[0082] Table 2 Detection of sulfonated phenolic resin type II

[0083]

[0084] As can be seen from Table 1 and Table 2, the sulfomethylphenolic resins obtained in Examples 1 to 3 were tested according to Sinopec Standard Q / SH0042-2007 and met both the requirements of Type I and Type II, showing good performance; whereas Comparative Example 1 met the requirements of Type I but not Type II; Comparative Example 2 met the requirements of Type II but not Type I; and Comparative Examples 3 and 4 failed to meet both the requirements of Type I and Type II.

[0085] In Comparative Example 1, due to the small amount of sulfonating agent added, the molecular weight of the synthesized sulfomethylphenolic resin is slightly larger and has a certain degree of sulfonation, so it has good performance when tested according to sulfonation type I, but due to the insufficient degree of sulfonation, its salt resistance is insufficient and the viscosity is high; in Comparative Example 2, the amount of sulfonating agent is increased, but due to the increase in the proportion of the sulfonating agent, the condensation reaction is moderate, the reaction time is prolonged, and the relative molecular weight is not easy to grow, but due to the large number of sulfonated groups, the salt resistance is improved, and it can meet the requirements when tested according to type II, but due to the small molecular weight, the water loss according to type I is large; in Comparative Example 3, due to the accelerated dropwise addition of formaldehyde, the early reaction speed is too fast, easy to implosion, and the molecular weight distribution range of the synthesized product is wide, so whether it is according to type I or type II, the high temperature and high pressure filtration loss exceeds the standard; in Comparative Example 4, due to the change from three water additions to two water additions, the two water additions are too much, and the reaction temperature fluctuates more violently during the synthesis process, so the reaction is greatly affected. The synthesized product just meets the standard according to type II, but does not meet the standard according to type I.

[0086] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a sulfomethylphenolic resin, characterized in that: The following steps are involved: mixing phenol, a sulfonating agent and a catalyst to carry out a sulfonation reaction to obtain a sulfonated product; The mass ratio of the phenol to the sulfonating agent is 6-7:3.2-3.6; The catalyst is sodium sulfite; the mass ratio of phenol to catalyst is 6-7:3.2-3.6; mixing the sulfonated product with formaldehyde and performing a polymerization reaction to obtain a sulfomethylphenol-formaldehyde resin; The amount of the sulfonated product is calculated based on the phenol participating in the sulfonation reaction, and the mass ratio of the phenol to formaldehyde is 6-7:10-14; The polymerization reaction comprises sequentially performing a first polymerization reaction and a second polymerization reaction; water is added in batches during the second polymerization reaction; The viscosity of the reaction product obtained by the first polymerization reaction is 150 to 180 mPa·s; The second polymerization reaction comprises: adding water to the product of the first polymerization reaction to perform a first intermediate polymerization reaction to obtain a first intermediate polymerization product; adding water to the first intermediate polymer product for a second time to carry out a second intermediate polymerization reaction to obtain a second intermediate polymer product; adding water to the second intermediate polymerization product for a third time to carry out a third intermediate polymerization reaction; The amount of water added in the first, second and third steps is increased successively; The mass ratio of the first added water to the formaldehyde is 3:10-14; The mass ratio of the amount of water added in the second step to the formaldehyde is 5:10-14; The mass ratio of the third added water to the formaldehyde is 7:10-14.

2. The preparation method according to claim 1, characterized in that The sulfonating agent includes sodium bisulfite and / or sodium metabisulfite.

3. The preparation method according to claim 1 or 2, characterized in that The temperature of the sulfonation reaction is 70-80° C., and the time is 0.5-1.5 h.

4. The preparation method according to claim 1, characterized in that The temperature of the first polymerization reaction is 85-95°C.

5. The preparation method according to claim 1, characterized in that The temperature of the first intermediate polymerization reaction is 85-95° C.; the time of the first intermediate polymerization reaction is 1-1.5 hours.

6. The preparation method according to claim 1, characterized in that The temperature of the second intermediate polymerization reaction is 85-95° C.; the time of the second intermediate polymerization reaction is 1-1.5 hours.

7. The preparation method according to claim 1, characterized in that The temperature of the third intermediate polymerization reaction is 95-105° C.; the time of the third intermediate polymerization reaction is 1-2 hours.

8. The preparation method according to claim 1, characterized in that The mixing of the sulfonated product and formaldehyde is performed by dripping the formaldehyde into the sulfonated product; the dripping speed of the formaldehyde is 13-15 kg / min.

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