CN112546875A - Water treatment multilayer composite membrane with ceramic coating and preparation process thereof - Google Patents

Abstract

The invention discloses a water treatment multilayer composite membrane with a ceramic coating and a preparation process thereof, wherein the water treatment multilayer composite membrane comprises a polyethylene base membrane, a fiber base membrane and a ceramic coating, wherein the upper surface and the lower surface of the polyethylene base membrane are respectively coated with a layer of fiber base membrane, the outer surface of the fiber base membrane is coated with a layer of ceramic coating, the fiber base membrane comprises 5-10 parts of fibers, 2-5 parts of an adhesive and 1-3 parts of a dispersing agent, and the ceramic coating comprises 10-15 parts of porous ceramic particles, 2-4 parts of an adhesive, 3-5 parts of a pore-forming agent, 5-7 parts of an inorganic filler, 3-5 parts of a grinding aid, 1-3 parts of a curing agent, 1-3 parts of a dispersing agent, 2-4 parts of acetic anhydride and 3-5 parts of. The invention can achieve the purpose of sterilization by adding ethyl acetoacetate, the main material of alumina has a porous structure, has the advantages of large surface area, high strength and the like, can improve the performance of the product, and the doped molecular sieve and titanium dioxide can improve the strength of the membrane and the sterilization and filtration effects.

Description

Water treatment multilayer composite membrane with ceramic coating and preparation process thereof

Technical Field

The invention relates to the technical field of ceramic membrane preparation, in particular to a water treatment multilayer composite membrane with a ceramic coating and a preparation process thereof.

Background

The membrane separation technology is developed rapidly in recent years, has the advantages of high separation efficiency, convenient operation, energy conservation and the like, is widely applied to various fields, can be divided into inorganic membranes and organic polymer membranes according to the types of the membranes, is developed rapidly in ceramic membranes in the inorganic membranes, and is widely applied to the field of water treatment.

With the advancement of science and technology and industry, the tensile strength of common ceramic membranes on the market cannot meet the normal use requirements of people, a large amount of additives are required to be added to improve the performance of various aspects of products, and as the ceramic membranes need to pass through various steps in the preparation process, the structure of the additives added in a complex preparation environment is changed, so that the tensile strength of finished products cannot meet the expected design requirements, and the obtained products cannot meet the requirements of people in practical application, the invention of the multilayer composite membrane with the ceramic coating and the preparation process thereof is particularly important.

Disclosure of Invention

The present invention is directed to a multilayer composite film having a ceramic coating and a process for preparing the same, which solves the problems set forth in the background art.

In order to solve the technical problems, the invention provides the following technical scheme: the water treatment multilayer composite membrane with the ceramic coating comprises a polyethylene base membrane, a fiber base membrane and a ceramic coating, wherein a layer of fiber base membrane is respectively coated on the upper surface and the lower surface of the polyethylene base membrane, a layer of ceramic coating is coated on the outer surface of the fiber base membrane, and the fiber base membrane comprises the following raw materials in parts by weight, 5-10 parts of fibers, 2-5 parts of an adhesive and 1-3 parts of a dispersing agent.

Furthermore, the ceramic coating comprises the following raw materials, by weight, 10-15 parts of porous ceramic particles, 2-4 parts of an adhesive, 3-5 parts of a pore-forming agent, 5-7 parts of an inorganic filler, 3-5 parts of a grinding aid, 1-3 parts of a curing agent, 1-3 parts of a dispersing agent, 2-4 parts of acetic anhydride and 3-5 parts of ethyl acetoacetate.

Further, the thickness of the polyvinyl film is 5-10 μm, and the pore size is 25-35 μm.

Further, the grinding aid is a mixture of ethylene glycol and stearic acid.

Further, the adhesive is any one or a mixture of polyvinyl alcohol, ethylene-vinyl acetate copolymer and copolymer of acrylic acid and acrylonitrile.

Further, the porous ceramic particles are a mixture of alumina, aluminum hydroxide, aluminum chloride, aluminum, titanium dioxide and a molecular sieve.

Further, the fiber is any one or a mixture of more of polyamide, polyimide and para-aramid, the pore-forming agent is any one or a mixture of two of urea and phenolic aldehyde, and the inorganic filler is any one or a mixture of more of aluminum silicate, ferric silicate and magnesium silicate.

A process for preparing the multi-layer composite membrane with ceramic coating for water treatment includes such steps as preparing the composite membrane,

(1) adding a dispersing agent and deionized water into the fibers, stirring, adding polyvinyl alcohol and an ethylene-vinyl acetate copolymer after uniformly stirring to obtain fiber slurry;

(2) coating the fiber slurry on the surface of a polyethylene base film to obtain the polyethylene base film coated with the fiber base film;

(3) polishing aluminum for 10-15min, adding aluminum oxide, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve, putting into a ball mill for grinding, and adding a grinding aid to obtain a ceramic powder mixture;

according to the invention, grinding aid ethylene glycol and stearic acid are added in the grinding process, so that the grinding efficiency can be improved, the ground ceramic powder is uniform in size, the contact area is increased in the subsequent process of preparing the metal alcohol substance, the reaction is more complete, the product quality is further ensured, the energy consumption is reduced, and the added ethylene glycol can be used as a raw material for preparing the metal alcohol, so that the preparation cost is reduced.

(4) Dissolving an adhesive in an ethylene glycol solution to obtain an adhesive solution;

(5) adding pyridine into the ceramic powder mixture, stirring, adding a pore-forming agent, stirring, adding acetic anhydride, stirring and heating, controlling the temperature to be 30-40 ℃, putting into a closed container, introducing hydrogen and nitrogen, heating, controlling the temperature to be 70-80 ℃, reacting for 10-15min, adding ethyl acetoacetate, inorganic filler, dispersant, deionized water and adhesive solution, stirring, heating, controlling the temperature to be 30-40 ℃, and stirring until the mixture becomes gel-like to obtain coating slurry;

the method comprises the steps of selecting alumina, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve as a support body, adding pyridine as a catalyst, reacting metals such as aluminum, aluminum chloride and titanium dioxide, metal oxides, metal chlorides and metal hydroxides with ethylene glycol to generate metal alcohol substances, adding an initiator of acetic anhydride, performing water and alcohol loss polymerization on the metal alcohol substances to form gel, adding ethyl acetoacetate, aluminum silicate, ferric silicate, a dispersing agent and an adhesive solution to obtain coating slurry, and coating the coating slurry to increase the overall tensile strength of a product and improve the adhesion.

The invention adds pyridine as a catalyst, the addition of the catalyst can enable the reaction to normally occur, but because the catalyst is not consumed and is extremely difficult to extract, the strength of the product and the adhesion degree between films are influenced, if the addition amount is too large, the qualification rate of the product is reduced, and the service life is reduced.

In the process of preparing the gel, hydrolysis reaction, dehydration polycondensation and alcohol loss polycondensation are doped, the hydrolysis reaction can generate water, the dehydration polycondensation can consume the water, the dehydration polymerization degree can be increased due to excessive water, the hydrolysis reaction can be increased due to too low water content, therefore, in order to keep the balance of the reaction and ensure the polymerization degree of the metal alcohol and the performance of a product film, the amount of added deionized water needs to be controlled, the proper deionized water content in the preparation process is ensured, the water can be added due to too low water content, the treatment cannot be carried out due to excessive water content, the tensile strength, the adhesive force and the use effect of the product are finally reduced, acetamide generated by the reaction of acetic anhydride and pyridine can also be used as water of the water absorption part of the water absorbent, the water content can be controlled, and the comprehensive performance of the product is ensured.

The reaction of acetic anhydride and pyridine can remove residual pyridine, ensure the stable performance of the product, but the reaction also produces the byproduct butanedione which can be removed as impurity through subsequent drying and sintering, but the volatilized ketone gas can cause damage to the human environment, so the invention selects the method by adopting the molecular sieve in the presence of the molecular sieve, the ketone gas is reduced by hydrogenation to obtain butanediol, the butanediol can better play the role of the adhesive as a solvent, and can also absorb water to avoid the phenomenon that the product cracks because the water is lost too fast in the preparation process, further improving the tensile strength, adhesive force and using effect of the product, and removing the byproduct butanedione, thereby reducing the harm of volatilized ketone gas to human bodies and environment.

(6) And (3) coating the coating slurry on the outer surface of the fiber-coated base film obtained in the step (2), drying in vacuum at the temperature of 100-150 ℃, and sintering at the temperature of 200-300 ℃ to obtain the multilayer composite film with the ceramic coating.

Further, in the step (2), the fiber pulp is coated to a thickness of 2-5 μm.

Compared with the prior art, the invention has the following beneficial effects: the composite membrane after ceramic coating has the advantages of strong chemical stability, acid and alkali resistance, high mechanical strength, reverse cleaning, blockage reduction, strong antimicrobial capability, long service life and the like, the ethyl acetoacetate is added to play a role in sterilization, the main material of alumina has a porous structure, has the advantages of large surface area, high strength and the like, the performance of the product can be improved, and the doped molecular sieve and titanium dioxide can increase the strength of the membrane and the sterilization and filtration effects.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all 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

The water treatment multilayer composite membrane with the ceramic coating comprises a polyethylene base membrane, a fiber base membrane and a ceramic coating, wherein a layer of fiber base membrane is respectively coated on the upper surface and the lower surface of the polyethylene base membrane, a layer of ceramic coating is coated on the outer surface of the fiber base membrane, and the fiber base membrane comprises the following raw materials in parts by weight, 5 parts of fibers, 2 parts of an adhesive and 1 part of a dispersing agent.

The ceramic coating comprises the following raw materials, by weight, 10 parts of porous ceramic particles, 2 parts of an adhesive, 3 parts of a pore-forming agent, 5 parts of an inorganic filler, 3 parts of a grinding aid, 1 part of a curing agent, 1 part of a dispersing agent, 2 parts of acetic anhydride and 3 parts of ethyl acetoacetate.

The thickness of the polyvinyl film is 5 μm, and the pore size is 25 μm.

The grinding aid is a mixture of ethylene glycol and stearic acid.

The adhesive is any one or mixture of polyvinyl alcohol, ethylene-vinyl acetate copolymer and copolymer of acrylic acid and acrylonitrile.

The porous ceramic particles are a mixture of alumina, aluminum hydroxide, aluminum chloride, aluminum, titanium dioxide and a molecular sieve.

The fiber is any one or mixture of more of polyamide, polyimide and para-aramid, the pore-forming agent is any one or mixture of two of urea and phenolic aldehyde, and the inorganic filler is any one or mixture of more of aluminum silicate, ferric silicate and magnesium silicate.

A process for preparing the multi-layer composite membrane with ceramic coating for water treatment includes such steps as preparing the composite membrane,

(1) adding a dispersing agent and deionized water into the fibers, stirring, adding polyvinyl alcohol and an ethylene-vinyl acetate copolymer after uniformly stirring to obtain fiber slurry;

(2) coating the fiber slurry on the surface of the polyethylene base film, wherein the coating thickness is 2 mu m, and obtaining the polyethylene base film coated with the fiber base film;

(3) polishing aluminum for 10min, adding aluminum oxide, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve, putting the mixture into a ball mill for grinding, and adding a grinding aid to obtain a ceramic powder mixture;

(4) dissolving an adhesive in an ethylene glycol solution to obtain an adhesive solution;

(5) adding pyridine into the ceramic powder mixture, stirring, adding a pore-forming agent, stirring, adding acetic anhydride, stirring and heating, controlling the temperature to be 30 ℃, putting into a closed container, introducing hydrogen and nitrogen, heating, controlling the temperature to be 70 ℃, reacting for 10min, adding ethyl acetoacetate, inorganic filler, dispersant, deionized water and adhesive solution, stirring, heating, controlling the temperature to be 30 ℃, and stirring until the mixture becomes gel-like to obtain coating slurry;

(6) and (3) coating the coating slurry on the outer surface of the fiber-coated base film obtained in the step (2), drying in vacuum at the temperature of 100 ℃, and sintering at the temperature of 200 ℃ to obtain the multilayer composite film with the ceramic coating.

Example 2

The water treatment multilayer composite membrane with the ceramic coating comprises a polyethylene base membrane, a fiber base membrane and a ceramic coating, wherein a layer of fiber base membrane is respectively coated on the upper surface and the lower surface of the polyethylene base membrane, a layer of ceramic coating is coated on the outer surface of the fiber base membrane, and the fiber base membrane comprises 8 parts of fiber, 3 parts of adhesive and 2 parts of dispersant according to the following raw materials in parts by weight.

The ceramic coating comprises the following raw materials, by weight, 13 parts of porous ceramic particles, 3 parts of an adhesive, 4 parts of a pore-forming agent, 6 parts of an inorganic filler, 4 parts of a grinding aid, 2 parts of a curing agent, 2 parts of a dispersing agent, 3 parts of acetic anhydride and 4 parts of ethyl acetoacetate.

The thickness of the polyvinyl film is 7 μm, and the pore size is 30 μm.

The grinding aid is a mixture of ethylene glycol and stearic acid.

The adhesive is any one or mixture of polyvinyl alcohol, ethylene-vinyl acetate copolymer and copolymer of acrylic acid and acrylonitrile.

The porous ceramic particles are a mixture of alumina, aluminum hydroxide, aluminum chloride, aluminum, titanium dioxide and a molecular sieve.

The fiber is any one or mixture of more of polyamide, polyimide and para-aramid, the pore-forming agent is any one or mixture of two of urea and phenolic aldehyde, and the inorganic filler is any one or mixture of more of aluminum silicate, ferric silicate and magnesium silicate.

A process for preparing the multi-layer composite membrane with ceramic coating for water treatment includes such steps as preparing the composite membrane,

(1) adding a dispersing agent and deionized water into the fibers, stirring, adding polyvinyl alcohol and an ethylene-vinyl acetate copolymer after uniformly stirring to obtain fiber slurry;

(2) coating the fiber slurry on the surface of the polyethylene base film, wherein the coating thickness is 3 mu m, and obtaining the polyethylene base film coated with the fiber base film;

(3) polishing aluminum for 13min, adding aluminum oxide, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve, putting the mixture into a ball mill for grinding, and adding a grinding aid to obtain a ceramic powder mixture;

(4) dissolving an adhesive in an ethylene glycol solution to obtain an adhesive solution;

(5) adding pyridine into the ceramic powder mixture, stirring, adding a pore-forming agent, stirring, adding acetic anhydride, stirring and heating, controlling the temperature to be 35 ℃, putting into a closed container, introducing hydrogen and nitrogen, heating, controlling the temperature to be 75 ℃, reacting for 13min, adding ethyl acetoacetate, inorganic filler, dispersant, deionized water and adhesive solution, stirring, heating, controlling the temperature to be 35 ℃, and stirring until the mixture becomes gel-like to obtain coating slurry;

(6) and (3) coating the coating slurry on the outer surface of the fiber-coated base film obtained in the step (2), drying in vacuum at the temperature of 130 ℃, and sintering at the temperature of 250 ℃ to obtain the multilayer composite film with the ceramic coating.

Example 3

The water treatment multilayer composite membrane with the ceramic coating comprises a polyethylene base membrane, a fiber base membrane and a ceramic coating, wherein a layer of fiber base membrane is respectively coated on the upper surface and the lower surface of the polyethylene base membrane, a layer of ceramic coating is coated on the outer surface of the fiber base membrane, and the fiber base membrane comprises the following raw materials in parts by weight, including 10 parts of fibers, 5 parts of an adhesive and 3 parts of a dispersing agent.

The ceramic coating comprises the following raw materials, by weight, 15 parts of porous ceramic particles, 4 parts of an adhesive, 5 parts of a pore-forming agent, 7 parts of an inorganic filler, 5 parts of a grinding aid, 3 parts of a curing agent, 3 parts of a dispersing agent, 4 parts of acetic anhydride and 5 parts of ethyl acetoacetate.

The thickness of the polyvinyl film is 10 μm, and the pore size is 35 μm.

The grinding aid is a mixture of ethylene glycol and stearic acid.

The adhesive is any one or mixture of polyvinyl alcohol, ethylene-vinyl acetate copolymer and copolymer of acrylic acid and acrylonitrile.

The porous ceramic particles are a mixture of alumina, aluminum hydroxide, aluminum chloride, aluminum, titanium dioxide and a molecular sieve.

The fiber is any one or mixture of more of polyamide, polyimide and para-aramid, the pore-forming agent is any one or mixture of two of urea and phenolic aldehyde, and the inorganic filler is any one or mixture of more of aluminum silicate, ferric silicate and magnesium silicate.

A water treatment multilayer composite membrane with a ceramic coating comprises the following steps,

(1) adding a dispersing agent and deionized water into the fibers, stirring, adding polyvinyl alcohol and an ethylene-vinyl acetate copolymer after uniformly stirring to obtain fiber slurry;

(2) coating the fiber slurry on the surface of the polyethylene base film, wherein the coating thickness is 5 mu m, and obtaining the polyethylene base film coated with the fiber base film;

(3) polishing aluminum for 15min, adding aluminum oxide, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve, putting the mixture into a ball mill for grinding, and adding a grinding aid to obtain a ceramic powder mixture;

(4) dissolving an adhesive in an ethylene glycol solution to obtain an adhesive solution;

(5) adding pyridine into the ceramic powder mixture, stirring, adding a pore-forming agent, stirring, adding acetic anhydride, stirring and heating, controlling the temperature to be 40 ℃, putting into a closed container, introducing hydrogen and nitrogen, heating, controlling the temperature to be 80 ℃, reacting for 15min, adding ethyl acetoacetate, inorganic filler, dispersant, deionized water and adhesive solution, stirring, heating, controlling the temperature to be 40 ℃, and stirring until the mixture becomes gel-like to obtain coating slurry;

(6) and (3) coating the coating slurry on the outer surface of the fiber-coated base film obtained in the step (2), drying in vacuum at the temperature of 150 ℃, and sintering at the temperature of 300 ℃ to obtain the multilayer composite film with the ceramic coating.

Comparative example 1

The water treatment multilayer composite membrane with the ceramic coating comprises a polyethylene base membrane, a fiber base membrane and a ceramic coating, wherein a layer of fiber base membrane is respectively coated on the upper surface and the lower surface of the polyethylene base membrane, a layer of ceramic coating is coated on the outer surface of the fiber base membrane, and the fiber base membrane comprises the following raw materials in parts by weight, including 10 parts of fibers, 5 parts of an adhesive and 3 parts of a dispersing agent.

The ceramic coating comprises the following raw materials, by weight, 15 parts of porous ceramic particles, 4 parts of an adhesive, 5 parts of a pore-forming agent, 7 parts of an inorganic filler, 5 parts of a grinding aid, 3 parts of a curing agent, 3 parts of a dispersing agent, 4 parts of ammonium persulfate and 5 parts of ethyl acetoacetate.

The thickness of the polyvinyl film is 10 μm, and the pore size is 35 μm.

The grinding aid is a mixture of ethylene glycol and stearic acid.

The adhesive is any one or mixture of polyvinyl alcohol, ethylene-vinyl acetate copolymer and copolymer of acrylic acid and acrylonitrile.

The porous ceramic particles are a mixture of alumina, aluminum hydroxide, aluminum chloride, aluminum, titanium dioxide and a molecular sieve.

The fiber is any one or mixture of more of polyamide, polyimide and para-aramid, the pore-forming agent is any one or mixture of two of urea and phenolic aldehyde, and the inorganic filler is any one or mixture of more of aluminum silicate, ferric silicate and magnesium silicate.

A water treatment multilayer composite membrane with a ceramic coating comprises the following steps,

(1) adding a dispersing agent and deionized water into the fibers, stirring, adding polyvinyl alcohol and an ethylene-vinyl acetate copolymer after uniformly stirring to obtain fiber slurry;

(2) coating the fiber slurry on the surface of the polyethylene base film, wherein the coating thickness is 5 mu m, and obtaining the polyethylene base film coated with the fiber base film;

(3) polishing aluminum for 15min, adding aluminum oxide, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve, putting the mixture into a ball mill for grinding, and adding a grinding aid to obtain a ceramic powder mixture;

(4) dissolving an adhesive in an ethylene glycol solution to obtain an adhesive solution;

(5) adding pyridine into the ceramic powder mixture, stirring, adding a pore-forming agent, stirring, adding ammonium persulfate, stirring and heating, controlling the temperature to be 40 ℃, putting into a closed container, introducing hydrogen and nitrogen, heating, controlling the temperature to be 80 ℃, reacting for 15min, adding ethyl acetoacetate, inorganic filler, dispersant, deionized water and adhesive solution, stirring, heating, controlling the temperature to be 40 ℃, and stirring until the mixture becomes gel-like to obtain coating slurry;

(6) and (3) coating the coating slurry on the outer surface of the fiber-coated base film obtained in the step (2), drying in vacuum at the temperature of 150 ℃, and sintering at the temperature of 300 ℃ to obtain the multilayer composite film with the ceramic coating.

Comparative example 2

The water treatment multilayer composite membrane with the ceramic coating comprises a polyethylene base membrane, a fiber base membrane and a ceramic coating, wherein a layer of fiber base membrane is respectively coated on the upper surface and the lower surface of the polyethylene base membrane, a layer of ceramic coating is coated on the outer surface of the fiber base membrane, and the fiber base membrane comprises the following raw materials in parts by weight, including 10 parts of fibers, 5 parts of an adhesive and 3 parts of a dispersing agent.

The ceramic coating comprises the following raw materials, by weight, 15 parts of porous ceramic particles, 4 parts of an adhesive, 5 parts of a pore-forming agent, 7 parts of an inorganic filler, 3 parts of a curing agent, 3 parts of a dispersing agent, 4 parts of acetic anhydride and 5 parts of ethyl acetoacetate.

The thickness of the polyvinyl film is 10 μm, and the pore size is 35 μm.

The adhesive is any one or mixture of polyvinyl alcohol, ethylene-vinyl acetate copolymer and copolymer of acrylic acid and acrylonitrile.

The porous ceramic particles are a mixture of alumina, aluminum hydroxide, aluminum chloride, aluminum, titanium dioxide and a molecular sieve.

The fiber is any one or mixture of more of polyamide, polyimide and para-aramid, the pore-forming agent is any one or mixture of two of urea and phenolic aldehyde, and the inorganic filler is any one or mixture of more of aluminum silicate, ferric silicate and magnesium silicate.

A process for preparing the multi-layer composite membrane with ceramic coating for water treatment includes such steps as preparing the composite membrane,

(1) adding a dispersing agent and deionized water into the fibers, stirring, adding polyvinyl alcohol and an ethylene-vinyl acetate copolymer after uniformly stirring to obtain fiber slurry;

(2) coating the fiber slurry on the surface of the polyethylene base film, wherein the coating thickness is 5 mu m, and obtaining the polyethylene base film coated with the fiber base film;

(3) polishing aluminum for 15min, adding aluminum oxide, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve, and putting the mixture into a ball mill for grinding to obtain ceramic powder;

(4) dissolving an adhesive in an ethylene glycol solution to obtain an adhesive solution;

(5) adding pyridine and ethylene glycol into ceramic powder, stirring, adding a pore-forming agent, stirring, adding acetic anhydride, stirring and heating, controlling the temperature to be 40 ℃, putting into a closed container, introducing hydrogen and nitrogen, heating, controlling the temperature to be 80 ℃, reacting for 15min, adding ethyl acetoacetate, inorganic filler, dispersant, deionized water and adhesive solution, stirring, heating, controlling the temperature to be 40 ℃, and stirring until the mixture becomes gel-like to obtain coating slurry;

(6) and (3) coating the coating slurry on the outer surface of the fiber-coated base film obtained in the step (2), drying in vacuum at the temperature of 150 ℃, and sintering at the temperature of 300 ℃ to obtain the multilayer composite film with the ceramic coating.

Experiment of

And (3) taking example 3 as a control, setting comparative examples 1 and 2, wherein the comparative example 1 adopts ammonium persulfate as an initiator, and the comparative example 2 does not add a grinding aid to prepare a control experiment.

Three samples of example 1, example 2, example 3, comparative example 1 and comparative example 2 were taken, and tensile strength and peel strength were measured, and the results were as follows,

experimental group	Tensile Strength (Kgf/cm)2)	Peel strength (N/m)
			Example 1	1684	93
Example 2	1672	91
			Example 3	1648	95
Comparative example 1	1594	87
			Comparative example 2	1572	82

Watch 1

The tensile strength and the peel strength of comparative example 1 were lower than those of examples 1, 2 and 3 because comparative example 1 employs ammonium persulfate as an initiator, so that pyridine and ammonium sulfate remain in the product, resulting in a decrease in the tensile strength and the peel strength of the product.

The tensile strength and the peel strength of the comparative example 2 are lower than those of the examples 1, 2 and 3, because the grinding aid is not added in the comparative example 2, the ground ceramic powder is not uniform in size, the reaction is incomplete in the subsequent metal alcohol preparation and polycondensation reaction, the quality of the product is reduced, the particle size is not uniform, the contact area of the ceramic coating and the fiber base film is reduced, and the peel strength is reduced.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. A water treatment multilayer composite membrane with a ceramic coating, characterized in that: the fiber base film comprises, by weight, 5-10 parts of fibers, 2-5 parts of an adhesive and 1-3 parts of a dispersing agent.

2. A water treatment multilayer composite membrane with a ceramic coating according to claim 1, characterized in that: the ceramic coating comprises the following raw materials, by weight, 10-15 parts of porous ceramic particles, 2-4 parts of an adhesive, 3-5 parts of a pore-forming agent, 5-7 parts of an inorganic filler, 3-5 parts of a grinding aid, 1-3 parts of a curing agent, 1-3 parts of a dispersing agent, 2-4 parts of acetic anhydride and 3-5 parts of ethyl acetoacetate.

3. A water treatment multilayer composite membrane with a ceramic coating according to claim 1, characterized in that: the thickness of the polyvinyl film is 5-10 μm, and the pore size is 25-35 μm.

4. A multilayer composite film having a ceramic coating according to claim 2, wherein: the grinding aid is a mixture of ethylene glycol and stearic acid.

5. A water treatment multilayer composite membrane with ceramic coating according to any of claims 1-2, characterized in that: the adhesive is any one or mixture of polyvinyl alcohol, ethylene-vinyl acetate copolymer and copolymer of acrylic acid and acrylonitrile.

6. A water treatment multilayer composite membrane with a ceramic coating according to claim 2, characterized in that: the porous ceramic particles are a mixture of alumina, aluminum hydroxide, aluminum chloride, aluminum, titanium dioxide and molecular sieves.

7. A water treatment multilayer composite membrane with a ceramic coating according to claim 2, characterized in that: the fiber is any one or mixture of more of polyamide, polyimide and para-aramid, the pore-forming agent is any one or mixture of two of urea and phenolic aldehyde, and the inorganic filler is any one or mixture of more of aluminum silicate, ferric silicate and magnesium silicate.

8. A preparation process of a water treatment multilayer composite membrane with a ceramic coating is characterized in that: the steps are as follows,

(1) adding a dispersing agent and deionized water into the fibers, stirring, adding polyvinyl alcohol and an ethylene-vinyl acetate copolymer after uniformly stirring to obtain fiber slurry;

(2) coating the fiber slurry on the surface of a polyethylene base film to obtain the polyethylene base film coated with the fiber base film;

(3) polishing aluminum for 10-15min, adding aluminum oxide, aluminum hydroxide, aluminum chloride, titanium dioxide and a molecular sieve, putting into a ball mill for grinding, and adding a grinding aid to obtain a ceramic powder mixture;

(4) dissolving an adhesive in an ethylene glycol solution to obtain an adhesive solution;

(5) adding pyridine into the ceramic powder mixture, stirring, adding a pore-forming agent, stirring, adding acetic anhydride, stirring and heating, controlling the temperature to be 30-40 ℃, putting into a closed container, introducing hydrogen and nitrogen, heating, controlling the temperature to be 70-80 ℃, reacting for 10-15min, adding ethyl acetoacetate, inorganic filler, dispersant, deionized water and adhesive solution, stirring, heating, controlling the temperature to be 30-40 ℃, and stirring until the mixture becomes gel-like to obtain coating slurry;

(6) and (3) coating the coating slurry on the outer surface of the fiber-coated base film obtained in the step (2), drying in vacuum at the temperature of 100-150 ℃, and sintering at the temperature of 200-300 ℃ to obtain the multilayer composite film with the ceramic coating.

9. The process of claim 8 for preparing a multilayer composite membrane with ceramic coating for water treatment, wherein: in the step (2), the thickness of the fiber pulp coating is 2-5 μm.