阅读说明：本技术 一种树脂的制备方法及制得的树脂、透明底漆 (Preparation method of resin, and prepared resin and transparent primer ) 是由 朱云成 陶善亮 朱伯承 王韬 唐桂明 龙艳梅 于 2021-06-24 设计创作，主要内容包括：本发明涉及废水处理领域,具体涉及一种树脂的制备方法及制备的树脂、透明底漆。树脂的制备方法包括回收酯化废水中醇类物质得混合醇,及利用混合醇制备树脂,所述利用混合醇制备树脂采用如下质量份数的原料：混合醇20份,单酸200-250份,苯酐250-300份,甘油150-200份,顺酐2-6份,次磷酸0.5-2份,第一回流二甲苯15-20份,第二回流二甲苯8-11份。本发明从酯化废水中充分提取回收醇类有机物及芳香族化合物,降低酯化废水中污染物浓度,减轻污水处理难度,同时将提取的醇类有机物与单酸反应制备成树脂,实现了酯化废水的资源化利用。(The invention relates to the field of wastewater treatment, in particular to a preparation method of resin, the prepared resin and a transparent primer. The preparation method of the resin comprises the steps of recovering alcohol substances in the esterification wastewater to obtain mixed alcohol, and preparing the resin by using the mixed alcohol, wherein the mixed alcohol is used for preparing the resin by adopting the following raw materials in parts by mass: 20 parts of mixed alcohol, 250 parts of monoacid, 300 parts of phthalic anhydride, 200 parts of glycerol, 2-6 parts of maleic anhydride, 0.5-2 parts of hypophosphorous acid, 15-20 parts of first reflux xylene and 8-11 parts of second reflux xylene. The method fully extracts and recycles the alcohol organic matters and the aromatic compounds from the esterification wastewater, reduces the concentration of pollutants in the esterification wastewater, reduces the difficulty of sewage treatment, and simultaneously prepares the extracted alcohol organic matters and the monoacid into resin through reaction, thereby realizing the resource utilization of the esterification wastewater.)

1. The preparation method of the resin is characterized by comprising the steps of recovering alcohol substances in esterification wastewater to obtain mixed alcohol and preparing the resin by using the mixed alcohol, wherein the mixed alcohol is used for preparing the resin by adopting the following raw materials in parts by mass: 20 parts of mixed alcohol, 250 parts of monoacid, 300 parts of phthalic anhydride, 200 parts of glycerol, 2-6 parts of maleic anhydride, 0.5-2 parts of hypophosphorous acid, 15-20 parts of first reflux xylene and 8-11 parts of second reflux xylene.

2. The method for preparing the resin according to claim 1, wherein the mixed alcohol is used for preparing the resin by adopting the following raw materials in parts by mass: 20 parts of mixed alcohol, 220 parts of monoacid, 290 parts of phthalic anhydride, 178 parts of glycerol, 5 parts of maleic anhydride, 0.7 part of hypophosphorous acid, 20 parts of first reflux xylene and 9 parts of second reflux xylene.

3. The method for preparing a resin according to claim 1 or 2, wherein the method for preparing a resin using a mixed alcohol comprises the steps of:

(1) putting mixed alcohol, monoacid, phthalic anhydride, glycerol, maleic anhydride, hypophosphorous acid and first reflux xylene into a reaction kettle in parts by weight, introducing nitrogen, heating the reaction kettle, and opening an upright column to cool water;

(2) the nitrogen is closed when the reaction kettle is heated to 140 ℃ and 150 ℃, the reaction kettle is continuously heated to 160 ℃ and 180 ℃ and is refluxed for 3 to 4 hours at constant temperature;

(3) after the reflux is finished, closing the cooling water of the upright column, adding second reflux dimethylbenzene into the reaction kettle, continuously heating, refluxing for 1h at the temperature of 180-;

(4) and introducing nitrogen after the central control detection is qualified, cooling the reaction kettle to below 180 ℃, adding a diluent, and homogenizing.

4. The method of claim 3, wherein the method of preparing the resin using the mixed alcohol further comprises: and (4) transferring the homogenized reaction solution obtained in the step (4) to a dilution kettle, pumping back for 1-2h, sampling, testing and discharging after passing a filter press.

5. The method according to claim 3, wherein the control detection index includes: the acid value of the sample directly tested is less than or equal to 18.5mgKOH/g, and the sample is diluted to a mass fraction of 52.5 percent and the viscosity of the sample is 10-20s/25 ℃ grid tube.

6. The method for preparing resin according to claim 1, wherein the step of recovering the alcohol from the esterification wastewater comprises the steps of:

(1) settling and separating an oil layer and a water layer;

(2) transferring the water layer to a distillation still for dehydration distillation, simultaneously opening a steam condensing device, controlling the temperature of a distillation head to be less than or equal to 110 ℃,

(3) stopping distillation when the temperature of distillate at the bottom of the kettle rises to 125-135 ℃, canning after the temperature is reduced, and recovering materials in the kettle to obtain the mixed alcohol.

7. A resin prepared by the process as claimed in any one of claims 1 to 6, characterized by an acid value of 12mgKOH/g or less, a viscosity of 55000 and 70000MPa s/30 ℃ and a solids content of 68 to 72%/(150 ℃ C.. times.1 h).

8. A transparent primer prepared from the resin of claim 7 is characterized by being prepared from the following raw materials in parts by mass: 50-65 parts of resin, 3-6 parts of toluene, 0.5-1 part of organic bentonite, 0.1-0.3 part of defoaming agent, 2-5 parts of magnesium stearate, 18-35 parts of talcum powder, 3-8 parts of xylene and 1-3 parts of butyl acetate.

9. The clear primer according to claim 8, wherein the preparation method comprises the steps of:

(1) uniformly stirring resin, toluene, organic bentonite and a defoaming agent at a first rotating speed;

(2) adding magnesium stearate, talcum powder and xylene into the material in the step (1), and stirring the mixture at a second rotating speed until the fineness of the mixture is below 50 mu m;

(3) and continuously stirring the mixture at the first rotating speed, adding butyl acetate, and adjusting the viscosity to obtain the product.

10. The transparent primer as claimed in claim 8, wherein the first rotation speed is 700-900r/min and the second rotation speed is 1800-2300 r/min.

Technical Field

The invention relates to the field of wastewater treatment, in particular to a preparation method of resin, and the prepared resin and transparent primer.

Background

In recent years, under the conditions of national policy support and rapid social and economic progress, the chemical industry of China is rapidly developed, and the esterification wastewater discharged in the production process is continuously increased, thereby forming a great threat to the environmental safety. The esterification wastewater, i.e. the wastewater generated in the esterification reaction, generally comes from the polyester production process.

In the discharging process of the esterification wastewater, a large amount of organic alcohol with low boiling point, such as glycol, diethylene glycol, glycerol, methyl propylene glycol and the like are contained, and the alcohol substances are dissolved in water and are not easy to separate from the water. In addition, part of benzene organic solvents in the esterification wastewater are difficult to biodegrade, so that the COD concentration of the esterification wastewater is high, and the common sewage treatment process is difficult to treat. The Fenton treatment process is adopted, even if the treatment can be carried out, the treatment cost can reach hundreds of yuan per ton. Not only the wastewater treatment cost is high, but also the waste of benzene and alcohol organic matters in the wastewater is caused.

Disclosure of Invention

In order to solve the problems, the invention provides a preparation method of resin, which is used for extracting alcohol organic matters in esterification wastewater and preparing the alcohol organic matters into the resin to realize resource utilization of the esterification wastewater, and the specific technical scheme is as follows:

the preparation method of the resin comprises the steps of recovering alcohol substances in the esterification wastewater to obtain mixed alcohol, and preparing the resin by using the mixed alcohol, wherein the mixed alcohol is used for preparing the resin by adopting the following raw materials in parts by weight: 20 parts of mixed alcohol, 250 parts of monoacid, 300 parts of phthalic anhydride, 200 parts of glycerol, 2-6 parts of maleic anhydride, 0.5-2 parts of hypophosphorous acid, 15-20 parts of first reflux xylene and 8-11 parts of second reflux xylene.

As a preferred embodiment of the preparation method of the resin of the present invention, the resin prepared by using the mixed alcohol adopts the following raw materials in parts by mass: 20 parts of mixed alcohol, 220 parts of monoacid, 290 parts of phthalic anhydride, 178 parts of glycerol, 5 parts of maleic anhydride, 0.7 part of hypophosphorous acid, 20 parts of first reflux xylene and 9 parts of second reflux xylene.

As a preferred embodiment of the method for preparing the resin according to the present invention, the method for preparing the resin using the mixed alcohol comprises the steps of:

(1) putting mixed alcohol, monoacid, phthalic anhydride, glycerol, maleic anhydride, hypophosphorous acid and first reflux xylene into a reaction kettle in sequence by weight, introducing nitrogen, heating the reaction kettle and opening an upright column to cool water;

(2) the nitrogen is closed when the reaction kettle is heated to 140 ℃ and 150 ℃, the reaction kettle is continuously heated to 160 ℃ and 180 ℃ and is refluxed for 3 to 4 hours at constant temperature;

(3) after the reflux is finished, closing the cooling water of the upright column, adding second reflux dimethylbenzene into the reaction kettle, continuously heating, refluxing for 1h at the temperature of 180-;

(4) introducing nitrogen after the central control detection is qualified, cooling the reaction kettle to below 180 ℃, adding a diluent, and homogenizing;

as a preferred embodiment of the method for preparing the resin of the present invention, the diluent is p-xylene or sec-butyl ester.

As a preferred embodiment of the method for preparing the resin according to the present invention, the method for preparing the resin using mixed alcohols further comprises: and (4) transferring the homogenized reaction solution obtained in the step (4) to a dilution kettle, pumping back for 1-2h, sampling, testing and discharging after passing a filter press. The back-pumping refers to pumping back and forth by a pump to accelerate the uniform stirring of the resin.

As a preferred embodiment of the preparation method of the resin, the center control detection indexes comprise: the acid value of the sample directly tested is less than or equal to 18.5mgKOH/g, and the sample is diluted to a mass fraction of 52.5 percent and the viscosity of the sample is 10-20s/25 ℃ grid tube.

As a preferred embodiment of the preparation method of the resin, the recovery of the alcohol substances in the esterification wastewater comprises the following steps:

(1) settling and separating an oil layer and a water layer;

(2) transferring the water layer to a distillation still for dehydration distillation, simultaneously opening a steam condensing device, controlling the temperature of a distillation head to be less than or equal to 110 ℃,

(3) stopping distillation when the temperature of distillate at the bottom of the kettle rises to 125-135 ℃, canning after the temperature is reduced, and recovering materials in the kettle to obtain the mixed alcohol.

As a preferred embodiment of the method for preparing the resin according to the present invention, the mixed alcohol comprises, in mass fraction: 50-54% of ethylene glycol, 12-15% of diethylene glycol, 11-15% of glycerol, 16-20% of methyl propylene glycol and the like.

The invention also provides the resin prepared by the method, the acid value is less than or equal to 12mgKOH/g, the viscosity is 55000-70000 MPa.s/30 ℃, and the solid content is 68-72%/(150 ℃ multiplied by 1 h).

The invention also provides a transparent primer prepared from the resin, which is prepared from the following raw materials in parts by mass: 50-65 parts of resin, 3-6 parts of toluene, 0.5-1 part of organic bentonite, 0.1-0.3 part of defoaming agent, 2-5 parts of magnesium stearate, 18-35 parts of talcum powder, 3-8 parts of xylene and 1-3 parts of butyl acetate.

The transparent primer is prepared from the following raw materials in parts by mass: 58 parts of resin, 4 parts of toluene, 0.8 part of organic bentonite, 0.15 part of defoaming agent, 3 parts of magnesium stearate, 26 parts of talcum powder, 5 parts of xylene and 2 parts of butyl acetate.

As a preferred embodiment of the transparent primer of the present invention, the preparation method comprises the following steps:

(1) uniformly stirring resin, toluene, organic bentonite and a defoaming agent at a first rotating speed;

(2) adding magnesium stearate, talcum powder and xylene into the material in the step (1), and stirring the mixture at a second rotating speed until the fineness of the mixture is below 50 mu m;

(3) and continuously stirring the mixture at the first rotating speed, adding butyl acetate, and adjusting the viscosity to obtain the product.

As a preferred embodiment of the transparent primer of the invention, the first rotation speed is 700-.

The preparation method of the resin, the prepared resin and the transparent primer have the following beneficial effects:

(1) the method selectively extracts and recycles the alcohol organic matters from the esterification wastewater, reduces the concentration of pollutants in the esterification wastewater, reduces the difficulty of sewage treatment, and simultaneously prepares the extracted alcohol organic matters and the monoacid into resin through reaction, thereby realizing the resource utilization of the esterification wastewater.

(2) The resin and the transparent primer prepared by the preparation method have the same performance indexes as those of conventional products, and have the effects of saving resources, reducing cost and protecting environment.

(3) The method for recovering the alcohol substances in the esterification wastewater adopts a sedimentation process before distillation to separate out a water layer and an oil layer, and organic matters containing benzene rings enter the oil layer, so that the method can selectively extract the alcohol substances required by resin preparation.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to specific embodiments, and it should be understood 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

This example illustrates the recovery of alcohols from esterification wastewater. The esterification wastewater of this example was obtained from a synthetic resin plant of a certain plant, and the raw water concentration COD was 152000mg/L, the total organic matter content in the water was 1842mg/L, and the main components were benzene organic solvent and alcohols.

The method for recovering the alcohols in the esterification wastewater comprises the following steps:

(1) settling, and separating oil layer and water layer. The method specifically comprises the following steps: the esterification wastewater is lifted to a standing settling tank through a collecting tank, the wastewater is stood and layered in the tank, organic substances which are insoluble in water float on the liquid level of a water layer due to the fact that the density of the wastewater is lower than that of water, an oil layer is formed, alcohol substances which are soluble in water such as ethylene glycol, diethylene glycol, glycerol, methyl propylene glycol and the like enter the water layer, and then the water layer is filled into a distillation kettle from the bottom of the tank through automatic liquid level control. The settling tank is provided with a lowest liquid level control device to avoid pumping the upper oil layer into the distillation still. After the settling tank is settled for many times, the floating oil and the solvent on the upper layer are periodically recovered according to the amount of the floating oil and the solvent.

(2) Transferring the water layer solution to a distillation still for dehydration distillation, simultaneously opening a steam condensing device, and controlling the temperature of a distillation head to be less than or equal to 110 ℃. The method specifically comprises the following steps: the temperature of the distillation kettle is controlled by adopting a temperature control regulating valve, the highest temperature in the kettle is set to be 125 ℃, the temperature of a distillation head is controlled not to exceed 110 ℃, the distilled mixed liquid is separated by a vertical fractionating tower, and steam is condensed into water by a horizontal heat exchanger and flows into a collection pool of a sewage station.

(3) Stopping distillation when the temperature of distillate at the bottom of the kettle rises to 125-135 ℃, canning after the temperature is reduced, and recovering materials in the kettle to obtain the mixed alcohol. The method specifically comprises the following steps: and (3) continuously circulating the mixed wastewater along with the distillation time, continuously increasing the content of organic alcohol in the mixed liquid in the distillation kettle, continuously increasing the temperature in the kettle from the first kettle distillate temperature at the beginning of the period to 100 ℃, and stopping introducing the water layer solution into the kettle bottom when the temperature reaches the set temperature of 125 ℃. And starting a cooling device to reduce the temperature to below 80 ℃, canning and recycling the materials in the kettle, and allowing distilled water to enter a sewage station regulating reservoir through a collecting tank.

The water content of the material at the bottom of the kettle after distillation is 15 percent through testing. The content of the product is as follows by gas chromatography analysis: 51.7% of ethylene glycol, 13.93% of diethylene glycol, 13.29% of glycerol, 18.57% of methyl propylene glycol and 2.51% of other components, wherein the main components are alcohol substances.

Example 2

This example illustrates the preparation of the resin. This example uses the mixed alcohol recovered in example 1 to prepare a resin.

The preparation method of the resin of the embodiment adopts the following raw materials in parts by mass: 20 parts of mixed alcohol, 220 parts of monoacid, 290 parts of phthalic anhydride, 178 parts of glycerol, 5 parts of maleic anhydride, 0.7 part of hypophosphorous acid, 20 parts of first reflux xylene and 9 parts of second reflux xylene.

The method for preparing the resin by using the mixed alcohol comprises the following steps:

(1) checking whether the reaction kettle, the pipeline, the electric instrument and the like of the production equipment run normally or not. Ensure the trouble-free use, ensure that a reaction kettle and a pipeline are clean and meet the feeding requirement.

(2) The mixed alcohol, the monoacid, the phthalic anhydride, the glycerol, the maleic anhydride, the hypophosphorous acid and the first reflux dimethylbenzene are put into a reaction kettle in sequence according to the parts by weight, and the second reflux dimethylbenzene is put into a head tank for standby. After the material is added, the feeding port is tightly covered, after the nitrogen is introduced for 15 minutes, the upright column cooling water is opened, and the temperature is raised.

(3) Under the premise of ensuring the oil temperature, the oil temperature rises to about 150 ℃ within 2h, the liquid is refluxed, and N is turned off after the reflux is stable₂Continuously heating, preserving the temperature for 1h at the temperature of 160-.

(4) After refluxing for 4h, the heat preservation is finished, the column cooling water is closed, the second refluxing dimethylbenzene is added, and the pot expansion is avoided. The temperature is continuously increased, the reflux is carried out for 1h at the temperature of 185-190 ℃ and the reflux esterification is carried out at the temperature of 195-205 ℃. Carrying out central control detection in the esterification process, wherein the central control detection indexes are as follows: the acid value of the sample directly tested is less than or equal to 18.5mgKOH/g, and the sample is diluted to a mass fraction of 52.5 percent, and the viscosity is 10-20s/25 ℃ format.

(5) And after the intermediate control is qualified, introducing nitrogen, cooling to below 180 ℃, slowly adding 207 parts of diluted dimethylbenzene for dilution, when the temperature of the kettle is reduced to below 160 ℃, adding the finished product into a dilution kettle, reserving about 5% of diluted dimethylbenzene for regulating the viscosity, washing the reaction kettle by using the rest solvent, and then adding the rest solvent into the dilution kettle.

(6) And opening a dilution kettle stirring and transferring pump, after transferring for 1h, sampling, adjusting viscosity and measuring fineness, and performing filter pressing and discharging after the materials are qualified.

The resin prepared in the embodiment is yellow transparent liquid, and the acid value is less than or equal to 12mgKOH/g, the viscosity is 55000-7000 MPa.s/format is 30 ℃, and the solid content is 68-72%/(150 ℃ multiplied by 1 h).

Example 3

This example illustrates the preparation of the resin. This example uses the mixed alcohol recovered in example 1 to prepare a resin.

The preparation method of the resin of the embodiment adopts the following raw materials in parts by mass: 20 parts of mixed alcohol, 200 parts of monoacid, 250 parts of phthalic anhydride, 150 parts of glycerol, 2 parts of maleic anhydride, 0.5 part of hypophosphorous acid, 15 parts of first reflux xylene and 8 parts of second reflux xylene.

The method for preparing the resin by using the mixed alcohol comprises the following steps:

(1) checking whether the reaction kettle, the pipeline, the electric instrument and the like of the production equipment run normally or not. Ensure the trouble-free use, ensure that a reaction kettle and a pipeline are clean and meet the feeding requirement.

(2) The mixed alcohol, the monoacid, the phthalic anhydride, the glycerol, the maleic anhydride, the hypophosphorous acid and the first reflux dimethylbenzene are put into a reaction kettle in sequence according to the parts by weight, and the second reflux dimethylbenzene is put into a head tank for standby. After the material is added, the feeding port is tightly covered, after the nitrogen is introduced for 15 minutes, the upright column cooling water is opened, and the temperature is raised.

(3) Under the premise of ensuring the oil temperature, the oil temperature rises to about 150 ℃ within 2h, the liquid is refluxed, and N is turned off after the reflux is stable₂Continuously heating, preserving the temperature for 1h at the temperature of 160-.

(4) After refluxing for 4h, the heat preservation is finished, the column cooling water is closed, the second refluxing dimethylbenzene is added, and the pot expansion is avoided. The temperature is continuously increased, the reflux is carried out for 1h at the temperature of 185-190 ℃ and the reflux esterification is carried out at the temperature of 195-205 ℃. Carrying out central control detection in the esterification process, wherein the central control detection indexes are as follows: the acid value of the sample directly tested is less than or equal to 18.5mgKOH/g, and the sample is diluted to a mass fraction of 52.5 percent, and the viscosity is 10-20s/25 ℃ format.

(5) And after the intermediate control is qualified, introducing nitrogen, cooling to below 180 ℃, slowly adding 200 parts of diluted dimethylbenzene for dilution, homogenizing, and discharging to obtain the product.

The resin prepared in the embodiment is yellow transparent liquid, and the acid value is less than or equal to 12mgKOH/g, the viscosity is 55000-7000 MPa.s/format is 30 ℃, and the solid content is 68-72%/(150 ℃ multiplied by 1 h).

Example 4

This example illustrates the preparation of the resin. This example uses the mixed alcohol recovered in example 1 to prepare a resin.

The preparation method of the resin of the embodiment adopts the following raw materials in parts by mass: 20 parts of mixed alcohol, 250 parts of monoacid, 300 parts of phthalic anhydride, 200 parts of glycerol, 6 parts of maleic anhydride, 2 parts of hypophosphorous acid, 20 parts of first reflux xylene and 11 parts of second reflux xylene.

The method for preparing the resin by using the mixed alcohol comprises the following steps:

(1) checking whether the reaction kettle, the pipeline, the electric instrument and the like of the production equipment run normally or not. Ensure the trouble-free use, ensure that a reaction kettle and a pipeline are clean and meet the feeding requirement.

(2) The mixed alcohol, the monoacid, the phthalic anhydride, the glycerol, the maleic anhydride, the hypophosphorous acid and the first reflux dimethylbenzene are put into a reaction kettle in sequence according to the parts by weight, and the second reflux dimethylbenzene is put into a head tank for standby. After the material is added, the feeding port is tightly covered, after the nitrogen is introduced for 15 minutes, the upright column cooling water is opened, and the temperature is raised.

(3) Under the premise of ensuring the oil temperature, the oil temperature rises to about 150 ℃ within 2h, the liquid is refluxed, and N is turned off after the reflux is stable₂Continuously heating, preserving the temperature for 1h at the temperature of 160-.

(4) After refluxing for 4h, the heat preservation is finished, the column cooling water is closed, the second refluxing dimethylbenzene is added, and the pot expansion is avoided. The temperature is continuously increased, the reflux is carried out for 1h at the temperature of 185-190 ℃ and the reflux esterification is carried out at the temperature of 195-205 ℃. Carrying out central control detection in the esterification process, wherein the central control detection indexes are as follows: the acid value of the sample directly tested is less than or equal to 18.5mgKOH/g, and the sample is diluted to a mass fraction of 52.5 percent, and the viscosity is 10-20s/25 ℃ format.

(5) And after the intermediate control is qualified, introducing nitrogen, cooling to below 180 ℃, slowly adding 250 parts of diluted dimethylbenzene for dilution, pouring the finished product into a dilution kettle when the kettle temperature is reduced to below 160 ℃, reserving about 5% of diluted solvent for regulating viscosity, washing the reaction kettle by the rest of the solvent, and then pouring the rest of the solvent into the dilution kettle.

(6) And opening a dilution kettle stirring and transferring pump, after transferring for 1h, sampling, adjusting viscosity and measuring fineness, and performing filter pressing and discharging after the materials are qualified.

The resin prepared in the embodiment is yellow transparent liquid, and the acid value is less than or equal to 12mgKOH/g, the viscosity is 55000-7000 MPa.s/format is 30 ℃, and the solid content is 68-72%/(150 ℃ multiplied by 1 h).

Example 5

This example illustrates a clear primer prepared using a resin. This example uses the resin prepared in example 2 as a starting material to prepare a clear primer.

The transparent primer is prepared from the following raw materials in parts by mass: 58 parts of resin obtained in example 2, 4 parts of toluene, 0.8 part of organic bentonite, 0.15 part of defoaming agent, 3 parts of magnesium stearate, 26 parts of 1250-mesh talcum powder, 5 parts of xylene and 2 parts of butyl acetate.

The preparation method comprises the following steps:

(1) uniformly stirring the resin obtained in the example 2, toluene, organic bentonite and a defoaming agent at the speed of 800 r/min;

(2) adding magnesium stearate, talcum powder and xylene into the material in the step (1), and stirring the mixture at 2000r/min until the fineness of the mixture is below 50 mu m;

(3) and continuously stirring the mixture at 800r/min, adding butyl acetate, and adjusting the viscosity to obtain the product.

Example 6

This example illustrates a clear primer prepared using a resin. This example uses the resin prepared in example 2 as a starting material to prepare a clear primer.

The transparent primer is prepared from the following raw materials in parts by mass: 50 parts of resin obtained in example 2, 4.5 parts of toluene, 1 part of organic bentonite, 0.1 part of defoaming agent, 2 parts of zinc stearate, 34 parts of 1250-mesh talcum powder, 5.4 parts of xylene and 3 parts of butyl acetate.

The preparation method comprises the following steps:

(1) uniformly stirring the resin obtained in the example 2, toluene, organic bentonite and a defoaming agent at 900 r/min;

(2) adding zinc stearate, talcum powder and xylene into the material in the step (1), and stirring the mixture at 2300r/min until the fineness of the mixture is below 50 mu m;

(3) and continuously stirring the mixture at 900r/min, adding butyl acetate, and adjusting the viscosity to obtain the product.

Example 7

This example illustrates a clear primer prepared using a resin. This example uses the resin prepared in example 2 as a starting material to prepare a clear primer.

The transparent primer is prepared from the following raw materials in parts by mass: 65 parts of resin obtained in example 2, 6 parts of toluene, 0.7 part of organic bentonite, 0.3 part of defoaming agent, 4 parts of zinc stearate, 18 parts of 1250-mesh talcum powder, 5 parts of xylene and 1 part of butyl acetate.

The preparation method comprises the following steps:

(1) uniformly stirring the resin obtained in the example 2, toluene, organic bentonite and a defoaming agent at the speed of 700 r/min;

(2) adding zinc stearate, talcum powder and xylene into the material in the step (1), and stirring the mixture at 1800r/min until the fineness of the mixture is below 50 mu m;

(3) and continuously stirring the mixture at 700r/min, adding butyl acetate, and adjusting the viscosity to obtain the product.

Comparative example

Compared with example 5, the difference is that the comparative example replaces the resin obtained in example 2 with the standard resin, and other raw materials and preparation methods are the same as example 5.

The clear primers prepared in examples 5-7 and comparative examples were tested and are specified in the following table:

the invention selectively extracts and recycles alcohol organic matters from the esterification wastewater, and prepares resin by using the alcohol organic matters, and the acidity, solid content, viscosity and other properties of the resin meet the requirements of conventional resin. Meanwhile, each index of the transparent primer prepared by the resin also meets the actual requirement, the effective reutilization of the esterification wastewater is realized, the resource is saved, the cost is reduced, and the environment-friendly effect is achieved.

The present invention has been further described with reference to specific embodiments, but it should be understood that the detailed description should not be construed as limiting the spirit and scope of the present invention, and various modifications made to the above-described embodiments by those of ordinary skill in the art after reading this specification are within the scope of the present invention.