Powdered interfacial agent prepared from a tertiary acetate redispersible latex powder and method for preparing the same

Abstract

The application discloses a powdery interface agent prepared from a tertiary acetate redispersible emulsion powder, relates to the technical field of building materials, and can be reduced into an aqueous emulsion by stirring and dispersing after adding water and is used for interface sealing of concrete and cement-based surfaces. The application prepares the redispersible emulsion powder from a tertiary acetate emulsion by a spray drying process, and the emulsion is prepared from the following components in parts by weight: vinyl acetate 50-80 parts, unsaturated acid monomer 1-5 parts, tertiary carbonic acid vinyl ester 30-50 parts, vinyl siloxane 0.3-3.0 parts, polyvinyl alcohol 5-20 parts, emulsifier 1-5 parts, oxidant 0.3-1.0 parts, and deionized water 95-105 parts. The finally prepared interface agent is prepared from the following components in parts by weight: tertiary acetate emulsion powder 76-84 parts; sodium bicarbonate 8-12 parts; cellulose ether 3-6 parts; and powdery defoaming agent 3-5 parts. The powdery interface agent prepared by the application is stable in performance, is not affected by low-temperature freezing, is convenient to transport, thereby saving a large amount of packaging materials and transportation cost, and meets the current national energy-saving and emission-reducing and environmental protection policies.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to a powdered interface agent prepared from tert-ethyl acetate redispersible latex powder and its preparation method. Background Technology

[0002] In building decoration and renovation, practice has shown that when preparing to apply putty or lay tiles on concrete or cement-based surfaces, the surface must first be treated with an interface agent. Interface agents are generally low-solids polymer emulsions, commonly known as "wall primer" or "floor primer." After being applied to unfinished cement-based walls and floors, they penetrate and absorb, enhancing interfacial adhesion and acting as an anchor; they also seal the capillaries of the cement-based surface, significantly reducing water absorption. When applying putty or tile adhesive, the moisture in the cement-based materials is retained for cement hydration, promoting the strength of the putty and tile adhesive; simultaneously, the bonding effect of the interface agent also enhances the adhesion between the material and the substrate. The home decoration market alone has a market capacity of tens of thousands of tons per year for interface agents (wall and floor primers).

[0003] However, most emulsion interface agents used in ordinary home decoration are polymer emulsions with a solid content of 8-15%, such as wall primers, floor primers, and self-leveling interface treatment agents used in interior decoration. After manufacturers compound the emulsions, they are packaged in plastic buckets and pallets before being transported to construction sites or markets for sale. Especially in winter, the issue of the emulsion freezing at low temperatures must be considered during transportation and storage. As a result, packaging costs, transportation, and labor costs account for more than 50% of the sales price, and the large amount of packaging materials consumed also leads to difficulties in the subsequent disposal of waste packaging materials and environmental pollution. Summary of the Invention

[0004] The purpose of this invention is to provide a powdered interface agent for the preparation of redispersible latex powder and a method thereof, thereby solving one or more of the problems in the prior art.

[0005] On the one hand, the powdered interface agent prepared from the redispersible latex powder of tert-ester provided by the present invention is formulated from the following components in parts by weight:

[0006] 76-84 parts of acetic acid latex powder;

[0007] 8-12 parts sodium bicarbonate;

[0008] 3-6 parts of cellulose ether,

[0009] 3-5 parts of powdered defoamer.

[0010] According to a specific embodiment of the present invention, the tert-ester latex powder is prepared from the following components in parts by weight:

[0011] 130-150 parts of tert-ethyl acetate copolymer emulsion;

[0012] 4-6 parts of film-forming aid;

[0013] 3-5 parts of polyvinyl alcohol;

[0014] 5-10 parts of anti-caking agent.

[0015] According to a specific embodiment of the present invention, the tert-ester copolymer emulsion is formulated from the following components in parts by weight:

[0016] Vinyl acetate 50-80 parts, unsaturated acid monomers 1-5 parts, vinyl tert-carbonate 30-50 parts, vinylsiloxane 0.3-3.0 parts, polyvinyl alcohol 5-20 parts, emulsifier 1-5 parts, oxidant 0.3-1.0 parts, deionized water 95-105 parts.

[0017] According to a specific embodiment of the present invention, the vinylsiloxane is selected from one or more of acryloyloxypropyl dimethoxysilane, methacryloyloxypropyl methyl diethoxysilane, methacryloyloxypropyl triisopropoxysilane, vinyltrimethoxysilane or its oligomers, and vinyltriethoxysilane or its oligomers.

[0018] According to a specific embodiment of the present invention, the unsaturated acid monomer is one of methacrylic acid, acrylic acid, and itaconic acid.

[0019] According to a specific embodiment of the present invention, the oxidant is one of hydrogen peroxide or persulfate, and the emulsifier is one or a mixture of two of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

[0020] On the other hand, the present invention also provides a method for preparing a powdered interface agent from tert-ester redispersible latex powder, comprising the following steps:

[0021] 1) Add polyvinyl alcohol, emulsifier, and deionized water to the flask, stir, and heat until completely dissolved;

[0022] 2) Prepare droplet A by mixing and stirring unsaturated acid monomers, ethylene tert-carbonate, and vinyl acetate;

[0023] 3) Mix the oxidant with deionized water and stir to prepare dropwise solution B;

[0024] 4) Add drop solution A, drop solution B, and vinylsiloxane to the flask in step one until drop solution A and vinylsiloxane are added completely, and drop solution B is added to 2 / 3 full. Then, keep the flask warm for 1 hour.

[0025] 5) Add the remaining 1 / 3 of the added liquid B, heat up to mature the emulsion, cool down and filter to obtain the tert-ester copolymer emulsion;

[0026] 6) The prepared tert-ester copolymer emulsion was spray-dried using a spray drying tower to obtain tert-ester redispersible latex powder;

[0027] 7) Weigh the prepared tert-ester redispersible latex powder, sodium bicarbonate, cellulose ether, and powdered defoamer according to the weight parts, and pour the weighed components into the mixer. There are no requirements on the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform to obtain the prepared powdered interface agent.

[0028] In a more preferred embodiment, the method for preparing the powdered interface agent from tert-ester redispersible latex powder includes the following steps:

[0029] 1) Add polyvinyl alcohol, emulsifier, and water to the flask, stir, and heat to above 80°C until completely dissolved;

[0030] 2) Prepare droplet A by mixing and stirring unsaturated acid monomers, ethylene tert-carbonate, and vinyl acetate;

[0031] 3) Mix the oxidant with water and stir to prepare dropwise solution B;

[0032] 4) Add dropwise liquid A and dropwise liquid B to the flask from step one. When dropwise liquid A is added to 1 / 3 of its volume, add vinylsiloxane to the remaining 1 / 3 of dropwise liquid A to obtain a mixture. Continue adding the mixture to the flask and continue adding dropwise liquid B until the mixture is completely added. After dropwise liquid B has been added to 2 / 3 of its volume, keep it warm for 1 hour. The dropwise liquid A should be added within 180-210 minutes. The time for adding dropwise liquid A here refers to the time for adding 2 / 3 of liquid A and the total time for the mixture, including the time for dropwise liquid B to be added to 2 / 3 of its total volume within 210-230 minutes.

[0033] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion.

[0034] 6) The prepared tert-ester copolymer emulsion is spray-dried in a spray drying tower according to the weight ratio specified above to obtain tert-ester redispersible latex powder;

[0035] 7) Weigh the prepared tert-ester redispersible latex powder, sodium bicarbonate, cellulose ether, and powdered defoamer according to the weight parts, and pour the weighed components into the mixer. There are no requirements on the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform to obtain the powdered interface agent.

[0036] The powdered interface agent described in this application is used in building decoration and renovation structures for interface sealing treatment of concrete or cement-based surfaces, sealing the capillaries of the cement system, and increasing interface adhesion.

[0037] The application method of the powdered interface agent for building decoration and renovation structures in this application includes the following steps: the powdered interface agent is redispersed in clean water with a mixer to form an emulsion, which is then prepared into an aqueous solution of about 10%, with a viscosity of 800-1500 mPa·s and a particle size of 150-300 nm. After stirring into a slurry, it can be applied.

[0038] Specifically, compared with the prior art, the present invention has the following outstanding advantages:

[0039] First, this invention prepares an emulsion that can be used as an interface agent. This emulsion can be spray-dried into a redispersible latex powder, and then formulated into a dry powder interface agent masterbatch by adjusting the dry powder composition ratio. When using it, the dry powder is added to a certain proportion of water and thoroughly stirred to disperse, resulting in a stable redispersible emulsion for use as an interface agent. The obtained redispersible emulsion exhibits considerable stability and can remain undivided for up to one week. Simultaneously, the prepared interface agent demonstrates good adhesion and high water resistance, significantly improving the bonding performance between new and old concrete interfaces.

[0040] Secondly, the interface agent obtained by the preparation method of this invention can be packaged in small bags as dry powder interface agent masterbatch, which is convenient for transportation and is not affected by ambient temperature. Therefore, it will not cause low-temperature freezing problems, saving a lot of packaging materials and transportation costs. Therefore, the powdered interface agent prepared by this invention can save a large number of plastic packaging barrels, and also conforms to the current national energy conservation, emission reduction and environmental protection policies, benefiting the present and future generations. Detailed Implementation

[0041] The present invention will be further described in detail below through embodiments.

[0042] Example 1

[0043] A powdered interface agent prepared from tert-ethyl acetate redispersible latex powder is formulated from the following components in parts by weight: 80 parts tert-ethyl acetate latex powder; 10 parts sodium bicarbonate; 3 parts cellulose ether; and 3 parts powdered defoamer. The tert-ethyl acetate latex powder is formulated from the following components in parts by weight: 145 parts tert-ethyl acetate emulsion; 5 parts film-forming aid; 4 parts polyvinyl alcohol; and 5 parts anti-caking agent.

[0044] In this embodiment, the unsaturated acid monomer is acrylic acid, the vinylsiloxane is methacryloxypropylmethyldiethoxysilane, and the oxidizing agent is sodium sulfate.

[0045] This acetic acid copolymer emulsion is formulated from the following components in parts by weight:

[0046] Vinyl acetate 60 parts, acrylic acid 3 parts, vinyl tert-carbonate 40 parts, methacryloyloxypropylmethyldiethoxysilane 0.3 parts, polyvinyl alcohol 10 parts, emulsifier 3 parts, oxidant 0.5 parts, deionized water 95 parts.

[0047] The preparation method of the powdered interface agent prepared from the redispersible latex powder of tert-ester in this embodiment includes the following steps:

[0048] 1) Add 10 parts polyvinyl alcohol, 3 parts emulsifier, and 85 parts deionized water to the flask to form a base mixture. Stir and heat to above 80°C to completely dissolve the PVA.

[0049] 2) Mix 3 parts acrylic acid, 40 parts ethylene tert-carbonate and 60 parts vinyl acetate to prepare droplet A;

[0050] 3) Dissolve 0.5 parts of sodium persulfate in 20 times its volume of deionized water (approximately 10 parts) to form dropwise solution B;

[0051] 4) At a controlled temperature of 81℃, add dropwise liquid A and dropwise liquid B to the flask in step one at a uniform rate. When dropwise liquid A is added to the remaining 1 / 3, add vinylsiloxane to the remaining 1 / 3 of dropwise liquid A to obtain a mixture, and continue to add it to the flask. Continue to add dropwise liquid B until the mixture is completely added. After dropwise liquid B is added to 2 / 3, keep warm for 1 hour. The dropwise liquid A is added within 3.5 hours. The time for adding dropwise liquid A here refers to the time for adding 2 / 3 of liquid A and the total time for the mixture. The dropwise liquid B is added to 2 / 3 of its total amount within 4 hours.

[0052] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion PM1.

[0053] 6) The prepared tert-ester copolymer emulsion was spray-dried in a spray drying tower according to the following weight ratio: 145 parts of tert-ester emulsion, 5 parts of film-forming aid, 4 parts of polyvinyl alcohol and 5 parts of anti-caking agent, to obtain tert-ester redispersible latex powder RDP1.

[0054] 7) Weigh 80 parts of the prepared tert-ester redispersible latex powder, 8 parts of the prepared sodium bicarbonate, 3 parts of cellulose ether, and 3 parts of powdered defoamer according to the weight ratio, and pour the weighed components into the mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform, and the powdered interface agent QG1 is obtained.

[0055] Example 2

[0056] A powdered interface agent prepared from tert-ethyl acetate redispersible latex powder is formulated from the following components in parts by weight: 78 parts tert-ethyl acetate latex powder; 8 parts sodium bicarbonate; 4 parts cellulose ether; and 4 parts powdered defoamer. The tert-ethyl acetate latex powder is formulated from the following components in parts by weight: 130 parts tert-ethyl acetate emulsion; 4 parts film-forming aid; 3 parts polyvinyl alcohol; and 6 parts anti-caking agent.

[0057] In this embodiment, the unsaturated acid monomer is acrylic acid, the vinylsiloxane is methacryloxypropylmethyldiethoxysilane, and the oxidant is sodium sulfate. The tert-ester copolymer emulsion is formulated from the following components in parts by weight:

[0058] 50 parts vinyl acetate, 1 part acrylic acid, 30 parts vinyl tert-carbonate, 0.5 parts methacryloxypropylmethyldiethoxysilane, 20 parts polyvinyl alcohol, 1 part emulsifier, 0.3 parts oxidant, and 95 parts deionized water.

[0059] The preparation method of the powdered interface agent prepared from the redispersible latex powder of tert-ester in this embodiment includes the following steps:

[0060] 1) Add 20 parts polyvinyl alcohol, 1 part emulsifier, and 85 parts deionized water to the flask to form a base mixture. Stir and heat to above 80°C to completely dissolve the PVA.

[0061] 2) Mix 1 part acrylic acid, 30 parts ethylene tert-carbonate and 50 parts vinyl acetate to prepare droplet A.

[0062] 3) Dissolve 0.3 parts of sodium persulfate in 20 times its volume of deionized water (approximately 10 parts) to form dropwise solution B;

[0063] 4) At a controlled temperature of 81℃, add dropwise liquid A and dropwise liquid B to the flask in step one at a uniform rate. When dropwise liquid A is added to the remaining 1 / 3, add vinylsiloxane to the remaining 1 / 3 of dropwise liquid A to obtain a mixture, and continue to add it to the flask. Continue to add dropwise liquid B until the mixture is completely added. After dropwise liquid B is added to 2 / 3, keep warm for 1 hour. The dropwise liquid A is added within 3.5 hours. The time for adding dropwise liquid A here refers to the time for adding 2 / 3 of liquid A and the total time for the mixture. The dropwise liquid B is added to 2 / 3 of its total amount within 4 hours.

[0064] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion PM2.

[0065] 6) The prepared tert-ester copolymer emulsion was spray-dried in a spray drying tower according to the following weight ratio: 130 parts of tert-ester emulsion, 4 parts of film-forming aid, 3 parts of polyvinyl alcohol and 6 parts of anti-caking agent, to obtain tert-ester redispersible latex powder RDP2.

[0066] 7) Weigh 78 parts of the prepared tert-ester redispersible latex powder and 8 parts of the prepared sodium bicarbonate, 4 parts of cellulose ether, and 4 parts of powdered defoamer according to the weight. Pour the weighed components into a mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform to obtain the powdered interface agent QG2.

[0067] Example 3

[0068] A powdered interface agent prepared from tert-ethyl acetate redispersible latex powder is formulated from the following components in parts by weight: 84 parts tert-ethyl acetate latex powder; 12 parts sodium bicarbonate; 6 parts cellulose ether; and 5 parts powdered defoamer. The tert-ethyl acetate latex powder is formulated from the following components in parts by weight: 150 parts tert-ethyl acetate emulsion; 6 parts film-forming aid; 5 parts polyvinyl alcohol; and 10 parts anti-caking agent.

[0069] In this embodiment, the unsaturated acid monomer is acrylic acid, the vinylsiloxane is methacryloxypropylmethyldiethoxysilane, and the oxidant is sodium sulfate. The tert-ester copolymer emulsion is formulated from the following components in parts by weight:

[0070] 80 parts vinyl acetate, 5 parts acrylic acid, 50 parts vinyl tert-carbonate, 3.0 parts methacryloxypropylmethyldiethoxysilane, 5 parts polyvinyl alcohol, 5 parts emulsifier, 1.0 part oxidant, and 105 parts deionized water.

[0071] The preparation method of the powdered interface agent prepared from the redispersible latex powder of tert-ester in this embodiment includes the following steps:

[0072] 1) Add 5 parts polyvinyl alcohol, 5 parts emulsifier, and 85 parts deionized water to the flask to form a base mixture. Stir and heat to above 80°C to completely dissolve the PVA.

[0073] 2) Mix 5 parts acrylic acid, 50 parts ethylene tert-carbonate and 80 parts vinyl acetate to prepare droplet A;

[0074] 3) Dissolve 1.0 part of sodium persulfate in 20 times its volume of deionized water (approximately 20 parts) to form dropwise solution B;

[0075] 4) At a controlled temperature of 81℃, add dropwise liquid A and dropwise liquid B to the flask in step one at a uniform rate. When dropwise liquid A is added to the remaining 1 / 3, add vinylsiloxane to the remaining 1 / 3 of dropwise liquid A to obtain a mixture, and continue to add it to the flask. Continue to add dropwise liquid B until the mixture is completely added. After dropwise liquid B is added to 2 / 3, keep warm for 1 hour. The dropwise liquid A is added within 3.5 hours. The time for adding dropwise liquid A here refers to the time for adding 2 / 3 of liquid A and the total time for the mixture. The dropwise liquid B is added to 2 / 3 of its total amount within 4 hours.

[0076] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion PM2.

[0077] 6) The prepared tert-ester copolymer emulsion was spray-dried in a spray drying tower according to the following weight ratio: 150 parts of tert-ester emulsion, 6 parts of film-forming aid, 5 parts of polyvinyl alcohol and 10 parts of anti-caking agent, to obtain tert-ester redispersible latex powder RDP2.

[0078] 7) Weigh out 84 parts of the prepared tert-ester redispersible latex powder, 12 parts of the prepared sodium bicarbonate, 6 parts of cellulose ether, and 5 parts of powdered defoamer according to the weight. Pour the weighed components into a mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform to obtain the powdered interface agent QG2.

[0079] Example 4

[0080] The powdered interface agent prepared from tert-ethyl acetate redispersible latex powder is formulated from the following components in parts by weight: 80 parts tert-ethyl acetate latex powder; 10 parts sodium bicarbonate; 3 parts cellulose ether; and 3 parts powdered defoamer.

[0081] This tert-grain acetic acid latex powder is formulated from the following components in parts by weight: 145 parts tert-grain acetic acid emulsion, 5 parts film-forming aid, 4 parts polyvinyl alcohol, and 5 parts anti-caking agent;

[0082] In this embodiment, the unsaturated acid monomer is methacrylic acid, the vinylsiloxane is methacryloxypropylmethyldiethoxysilane, and the oxidant is sodium sulfate. The tert-ester copolymer emulsion is formulated from the following components in parts by weight:

[0083] Vinyl acetate 60 parts, methacrylic acid 3 parts, ethylene tert-carbonate 40 parts, methacryloxypropylmethyldiethoxysilane 0.3 parts, polyvinyl alcohol 10 parts, emulsifier 3 parts, oxidant 0.5 parts, deionized water 95 parts.

[0084] The preparation method of the powdered interface agent prepared from the redispersible latex powder of tert-ester in this embodiment includes the following steps:

[0085] 1) Add 10 parts polyvinyl alcohol, 3 parts emulsifier, and 85 parts deionized water to the flask to form a base mixture. Stir and heat to above 80°C to completely dissolve the PVA.

[0086] 2) Mix 3 parts methacrylic acid, 40 parts ethylene tert-carbonate and 60 parts vinyl acetate to prepare droplet A;

[0087] 3) Dissolve 0.5 parts of sodium persulfate in 20 times its volume of deionized water (approximately 10 parts) to form dropwise solution B;

[0088] 4) At a controlled temperature of 81℃, add dropwise liquid A and dropwise liquid B to the flask in step one at a uniform rate. When dropwise liquid A is added to the remaining 1 / 3, add vinylsiloxane to the remaining 1 / 3 of dropwise liquid A to obtain a mixture, and continue to add it to the flask. Continue to add dropwise liquid B until the mixture is completely added. After dropwise liquid B is added to 2 / 3, keep warm for 1 hour. The dropwise liquid A is added within 3.5 hours. The time for adding dropwise liquid A here refers to the time for adding 2 / 3 of liquid A and the total time for the mixture. The dropwise liquid B is added to 2 / 3 of its total amount within 4 hours.

[0089] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion PM4.

[0090] 6) The prepared tert-ester copolymer emulsion was spray-dried in a spray drying tower according to the following weight ratio: 145 parts of tert-ester emulsion, 5 parts of film-forming aid, 4 parts of polyvinyl alcohol and 5 parts of anti-caking agent, to obtain tert-ester redispersible latex powder RDP4.

[0091] 7) Weigh 80 parts of the prepared tert-ester redispersible latex powder, 8 parts of the prepared sodium bicarbonate, 3 parts of cellulose ether, and 3 parts of powdered defoamer according to the weight ratio, and pour the weighed components into the mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform, and the powdered interface agent QG4 is obtained.

[0092] Example 5

[0093] The powdered interface agent prepared from tert-ethyl acetate redispersible latex powder is formulated from the following components in parts by weight: 80 parts tert-ethyl acetate latex powder; 10 parts sodium bicarbonate; 3 parts cellulose ether; and 3 parts powdered defoamer.

[0094] This tert-grain acetic acid latex powder is formulated from the following components in parts by weight: 145 parts tert-grain acetic acid emulsion, 5 parts film-forming aid, 4 parts polyvinyl alcohol, and 5 parts anti-caking agent;

[0095] In this embodiment, the unsaturated acid monomer is acrylic acid, the vinylsiloxane is methacryloxypropylmethyldiethoxysilane, and the oxidant is sodium sulfate. The tert-ester copolymer emulsion is formulated from the following components in parts by weight:

[0096] Vinyl acetate 60 parts, acrylic acid 3 parts, vinyl tert-carbonate 40 parts, methacryloyloxypropylmethyldiethoxysilane 0.3 parts, polyvinyl alcohol 10 parts, emulsifier 3 parts, oxidant 0.5 parts, deionized water 95 parts.

[0097] The preparation method of the powdered interface agent prepared from the redispersible latex powder of tert-ester in this embodiment includes the following steps:

[0098] 1) Add 10 parts polyvinyl alcohol, 3 parts emulsifier, and 85 parts deionized water to the flask to form a base mixture. Stir and heat to above 80°C to completely dissolve the PVA.

[0099] 2) Mix 3 parts acrylic acid, 40 parts ethylene tert-carbonate, 60 parts vinyl acetate, and 0.3 parts methacryloxypropylmethyldiethoxysilane to prepare dropwise solution A;

[0100] 3) Dissolve 0.5 parts of sodium persulfate in 20 times its volume of deionized water to form drop solution B;

[0101] 4) While controlling the temperature at 85℃, add dropwise liquid A and dropwise liquid B to the flask in step one at a uniform rate. Dropwise liquid A is added in 3.5 hours, and dropwise liquid B is added in 4 hours until 2 / 3 of its total volume is reached.

[0102] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion PM5.

[0103] 6) The prepared tert-ester copolymer emulsion was spray-dried in a spray drying tower according to the following weight ratio: 145 parts of tert-ester emulsion, 5 parts of film-forming aid, 4 parts of polyvinyl alcohol and 5 parts of anti-caking agent, to obtain tert-ester redispersible latex powder RDP5.

[0104] 7) Weigh 80 parts of the prepared tert-ester redispersible latex powder, 8 parts of the prepared sodium bicarbonate, 3 parts of cellulose ether, and 3 parts of powdered defoamer according to the weight ratio, and pour the weighed components into the mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform, and the powdered interface agent QG5 is obtained.

[0105] Example 6

[0106] The powdered interface agent prepared from tert-ethyl acetate redispersible latex powder is formulated from the following components in parts by weight: 80 parts tert-ethyl acetate latex powder; 10 parts sodium bicarbonate; 3 parts cellulose ether; and 3 parts powdered defoamer.

[0107] This tert-grain acetic acid latex powder is formulated from the following components in parts by weight: 145 parts tert-grain acetic acid emulsion, 5 parts film-forming aid, 4 parts polyvinyl alcohol, and 5 parts anti-caking agent;

[0108] In this embodiment, the unsaturated acid monomer is acrylic acid, the vinylsiloxane is methacryloxypropylmethyldiethoxysilane, and the oxidant is sodium sulfate. The tert-ester copolymer emulsion is formulated from the following components in parts by weight:

[0109] Vinyl acetate 60 parts, acrylic acid 3 parts, vinyl tert-carbonate 40 parts, methacryloyloxypropylmethyldiethoxysilane 0.3 parts, polyvinyl alcohol 10 parts, emulsifier 3 parts, oxidant 0.5 parts, deionized water 95 parts.

[0110] The preparation method of the powdered interface agent prepared from the redispersible latex powder of tert-ester in this embodiment includes the following steps:

[0111] 1) Add 10 parts polyvinyl alcohol, 3 parts emulsifier, and 85 parts deionized water to the flask to form a base mixture. Stir and heat to above 80°C to completely dissolve the PVA.

[0112] 2) Mix 3 parts acrylic acid, 40 parts ethylene tert-carbonate and 60 parts vinyl acetate to prepare droplet A;

[0113] 3) Dissolve 0.5 parts of sodium persulfate in 20 times its volume of deionized water (approximately 10 parts) to form dropwise solution B;

[0114] 4) While controlling the temperature at 85℃, add dropwise liquid A and dropwise liquid B to the flask in step one at a uniform rate. Dropwise liquid A should be added in 3.5 hours, and dropwise liquid B should be added in 4 hours until it reaches 2 / 3 of its total volume. After the dropwise liquid A is added, add 0.3 parts of methacryloyloxypropylmethyldiethoxysilane and add it in 10-15 minutes.

[0115] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion PM6.

[0116] 6) The prepared tert-ester copolymer emulsion was spray-dried in a spray drying tower according to the following weight ratio: 145 parts of tert-ester emulsion, 5 parts of film-forming aid, 4 parts of polyvinyl alcohol and 5 parts of anti-caking agent, to obtain tert-ester redispersible latex powder RDP6.

[0117] 7) Weigh 80 parts of the prepared tert-ester redispersible latex powder, 8 parts of the prepared sodium bicarbonate, 3 parts of cellulose ether, and 3 parts of powdered defoamer according to the weight, and pour the weighed components into the mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform to obtain the powdered interface agent QG6.

[0118] Example 7

[0119] The powdered interface agent prepared from tert-ethyl acetate redispersible latex powder is formulated from the following components in parts by weight: 80 parts tert-ethyl acetate latex powder; 10 parts sodium bicarbonate; 3 parts cellulose ether; and 3 parts powdered defoamer.

[0120] This tert-grain acetic acid latex powder is formulated from the following components in parts by weight: 145 parts tert-grain acetic acid emulsion, 5 parts film-forming aid, 4 parts polyvinyl alcohol, and 5 parts anti-caking agent;

[0121] In this embodiment, the unsaturated acid monomer is acrylic acid, the vinylsiloxane is vinyltriethoxysilane, and the oxidant is sodium sulfate. The tert-ester copolymer emulsion is formulated from the following components in parts by weight:

[0122] Vinyl acetate 60 parts, acrylic acid 3 parts, vinyl tert-carbonate 40 parts, vinyltriethoxysilane 0.3 parts, polyvinyl alcohol 10 parts, emulsifier 3 parts, oxidant 0.5 parts, deionized water 95 parts.

[0123] The preparation method of the powdered interface agent prepared from the redispersible latex powder of tert-ester in this embodiment includes the following steps:

[0124] 1) Add 10 parts polyvinyl alcohol, 3 parts emulsifier, and 85 parts deionized water to the flask to form a base mixture. Stir and heat to above 80°C to completely dissolve the PVA.

[0125] 2) Mix 3 parts methacrylic acid, 40 parts ethylene tert-carbonate and 60 parts vinyl acetate to prepare droplet A;

[0126] 3) Dissolve 0.5 parts of sodium persulfate in 20 times its volume of deionized water (approximately 10 parts) to form dropwise solution B;

[0127] 4) While controlling the temperature at 85℃, add dropwise liquid A and dropwise liquid B to the flask in step one at a uniform rate. When dropwise liquid A is added to the remaining 1 / 3, add vinylsiloxane to the remaining 1 / 3 of dropwise liquid A to obtain a mixture, and continue to add it to the flask. Continue to add dropwise liquid B until the mixture is completely added. After dropwise liquid B is added to 2 / 3, keep it at the temperature for 1 hour. The dropwise liquid A is controlled to be added in 3.5 hours. The time for adding dropwise liquid A here refers to the time for adding 2 / 3 of liquid A and the total time for the mixture. The dropwise liquid B is added to 2 / 3 of its total amount in 4 hours.

[0128] 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion PM7.

[0129] 6) The prepared tert-ester copolymer emulsion was spray-dried in a spray drying tower according to the following weight ratio: 145 parts of tert-ester emulsion, 5 parts of film-forming aid, 4 parts of polyvinyl alcohol and 5 parts of anti-caking agent, to obtain tert-ester redispersible latex powder RDP7.

[0130] 7) Weigh 80 parts of the prepared tert-ester redispersible latex powder, 8 parts of the prepared sodium bicarbonate, 3 parts of cellulose ether, and 3 parts of powdered defoamer according to the weight ratio, and pour the weighed components into the mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform, and the powdered interface agent QG7 is obtained.

[0131] Comparative Example 1

[0132] In the preparation of the powdered interface agent made from tert-ethyl acetate redispersible latex powder, except that tert-ethyl acetate is not added to the raw materials, the other preparation processes and component ratios are the same as in Example 1.

[0133] Comparison Example 2

[0134] In the preparation of the powdered interface agent made from tert-ethyl acetate redispersible latex powder, except that acrylic acid is not added to the raw materials, the other preparation process and component ratios are the same as in Example 1.

[0135] Comparison Example 3

[0136] In the preparation of the powdered interface agent made from tert-ethyl acetate redispersible latex powder, except that methacryloyloxypropyl dimethoxysilane is not added to the raw materials, the other preparation process and component ratios are the same as in Example 1.

[0137] Comparison Example 4

[0138] In the preparation of the powdered interface agent made from tert-ester redispersible latex powder, except that cellulose ether is not added in the final latex powder mixing, the other preparation process and component ratios are the same as in Example 1.

[0139] Comparative test

[0140] Powdered interface agents prepared by Examples 1-7 and Comparative Examples 1-4 were redispersed in water to form an emulsion with a solid content of 10% by weight. The redispersibility and ease of dispersion were examined, and the stability of the redispersed solution was observed for one week.

[0141] All samples were stirred quickly for 1 minute and slowly for 1 minute using a handheld electric mixer, and then filtered through a 150-mesh filter cloth. Continuous observation was conducted for 7 days, noting the proportion of water in the upper layer relative to the total liquid level.

[0142] The test data are shown in Tables 1 and 2 below, where Table 1 shows the ease of dispersion and the stability of the dispersion.

[0143] Table 1

[0144]

[0145] As shown in Table 1, the differences in effects between the seven embodiments and the four comparative examples are as follows:

[0146] Examples 1-6 show that the prepared dispersions exhibit good stability, high redispersibility, and low residue rates. Comparative Example 1, which did not contain ethylene tert-carbonate in its raw materials, showed relatively poorer stability compared to Examples 1-6. According to the table, Examples 1-7 all used acrylic acid monomers. Comparative Example 2 had the same preparation process and component ratio as Example 1, but did not add unsaturated acid monomers. Comparative Example 2 showed poorer stability and more residue, indicating that adding carboxyl monomers can significantly improve the stability of the redispersible dispersion, while also promoting easier dispersion of the adhesive powder and reducing redispersible residue. Based on the preparation processes of Examples 7 and 1, although Example 7 also used acrylic acid, it used vinyltriethoxysilane, resulting in relatively more residue and poorer redispersibility. This also indicates that the choice of vinylsiloxane affects the stability of the redispersible dispersion.

[0147] Data from Example 1 and Comparative Example 4 show that without the addition of cellulose ether, the stability on the third day was 1 / 3, and the stability on the seventh day was greater than 1 / 2. This indicates that the addition of cellulose ether in the later stages of the formulation can improve viscosity and is crucial for stability.

[0148] Table 2 shows the data for the powdered interface agent in each example and comparative example. After being prepared into a 10% emulsion, it was applied to the interface of the mortar block to test the bonding strength and water resistance of the interior wall putty. The blank samples were not coated with interface agent. According to standard JC / T298-2010 "Building Interior Putty", the standard bonding strength is ≥0.5MPa, and the water immersion strength is ≥0.3MPa.

[0149] Table 2

[0150]

[0151]

[0152] According to the data in Table 2, after treating the standard mortar block with an interface agent, the bonding strength and water resistance of the putty were improved to a certain extent. Compared with the blank sample, the strength of Example 1 increased by more than 1 times. Example 1 and Comparative Example 1 show that the addition of ethylene tert-carbonate can improve the water resistance. Examples 1, 6, 7 and Comparative Example 3 show that the addition of vinylsiloxane can improve the bonding strength and water resistance by more than 50%. The preparation process and component ratio of Comparative Example 4 are the same as those of Example 1, but no cellulose ether is added. The performance is good, but according to Table 1, its stability is not good.

[0153] Table 3 shows a comparison of the physical properties and synthetic stability of the synthetic emulsions.

[0154] Table 3

[0155]

[0156] As shown in Table 3, and in conjunction with Table 2, Examples 1 and 4 demonstrate that the choice of carboxyl monomer affects the synthesis stability, with acrylic acid providing better stability. Examples 1 and 7 show that Example 7 has a high residue rate and coarser particle size, thus affecting the stability of the redispersed emulsion. This indicates that the choice of vinylsiloxane has a significant impact on the viscosity and particle size of the synthesized emulsion; excessively large particle size reduces the stability of the redispersed liquid. Examples 1 and Comparative Example 1 show that the addition of ethylene tert-carbonate helps stabilize the copolymer emulsion, resulting in finer particle size and less residue. In Example 3, the high proportions of silane and acrylic acid resulted in a relatively high emulsion viscosity, leading to coarser powder particles and more residue. However, the powder prepared as an interface agent meets the standard requirements. Examples 1-7 and Comparative Example 3 show that although the addition of vinylsiloxane has a certain impact on the stability of the emulsion synthesis, with the lowest residue rate observed without silane, the residue can be effectively controlled by selecting a suitable silane.

[0157] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these should also be considered within the scope of protection of the invention.

Claims

1. A powdered interface agent prepared from tert-ethyl acetate redispersible latex powder, characterized in that, It is prepared from the following components in parts by weight: 76-84 parts of acetic acid latex powder; 8-12 parts sodium bicarbonate; 3-6 parts of cellulose ether, 3-5 parts of powdered defoamer; The tert-ethyl acetate latex powder is formulated from the following components in parts by weight: 130-150 parts of tert-ethyl acetate copolymer emulsion; 4-6 parts of film-forming aid; 3-5 parts of polyvinyl alcohol; 5-10 parts of anti-caking agent; The tert-ester copolymer emulsion is formulated from the following components in parts by weight: The composition includes 50-80 parts vinyl acetate, 1-5 parts unsaturated acid monomers, 30-50 parts ethylene tert-carbonate, 0.3-3.0 parts vinylsiloxane, 5-20 parts polyvinyl alcohol, 1-5 parts emulsifier, 0.3-1.0 parts oxidant, and 95-105 parts deionized water; wherein the oxidant is persulfate. The preparation method of tert-ester latex powder as a powdered interface agent includes the following steps: 1) Add polyvinyl alcohol, emulsifier, and deionized water to the flask, stir, and heat until completely dissolved; 2) Prepare droplet A by mixing and stirring unsaturated acid monomers, ethylene tert-carbonate, and vinyl acetate; 3) Mix the oxidant with deionized water and stir to prepare dropwise solution B; 4) Add drop solution A, drop solution B, and vinylsiloxane to the flask in 1) until drop solution A and vinylsiloxane are added completely, and drop solution B is added to 2 / 3 full. Then, keep the flask warm for 1 hour. 5) Add the remaining 1 / 3 of the added liquid B, heat up to mature the emulsion, cool down and filter to obtain the tert-ester copolymer emulsion; 6) The prepared tert-ester copolymer emulsion, film-forming aid, polyvinyl alcohol and anti-caking agent are spray-dried in a spray drying tower according to the weight ratio to obtain tert-ester latex powder; 7) Weigh the prepared tert-ester latex powder, sodium bicarbonate, cellulose ether, and powdered defoamer according to the weight parts, and pour the weighed components into the mixer. There are no requirements on the order of pouring the materials. Mix evenly to obtain the prepared powdered interface agent.

2. The powdered interface agent prepared from the redispersible latex powder according to claim 1, characterized in that, The vinylsiloxane is selected from one or more of acryloyloxypropyl dimethoxysilane, methacryloxypropyl methyl diethoxysilane, methacryloxypropyl triisopropoxysilane, vinyltrimethoxysilane or its oligomers, and vinyltriethoxysilane or its oligomers.

3. The powdered interface agent prepared from the redispersible latex powder according to claim 1, characterized in that, The unsaturated acid monomer is one of methacrylic acid, acrylic acid, and itaconic acid.

4. The powdered interface agent prepared from the redispersible latex powder according to claim 2, characterized in that, The emulsifier is one or both of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

5. The method for preparing the powdered interface agent from the redispersible latex powder according to any one of claims 1 to 4, characterized in that, Includes the following steps: 1) Add polyvinyl alcohol, emulsifier, and water to the flask, stir, and heat to above 80°C to completely dissolve them; 2) Prepare droplet A by mixing and stirring unsaturated acid monomers, ethylene tert-carbonate, and vinyl acetate; 3) Mix the oxidant with water and stir to prepare dropwise solution B; 4) Add dropwise liquid A and dropwise liquid B to the flask in 1). When dropwise liquid A is added to 1 / 3 of its volume, add vinylsiloxane to the remaining dropwise liquid A to obtain a mixture. Continue to add the mixture to the flask and continue adding dropwise liquid B until the mixture is completely added. After dropwise liquid B is added to 2 / 3 of its volume, keep it warm for 1 hour. Dropwise liquid A should be added within 180-210 minutes, and dropwise liquid B should be added within 210-230 minutes to 2 / 3 of its total volume. 5) Add the remaining 1 / 3 of the added liquid B, and heat to above 90°C to mature the emulsion for 1 hour. When the temperature drops to 40°C, filter the material to obtain the tert-ester copolymer emulsion. 6) The prepared tert-ester copolymer emulsion, film-forming aid, polyvinyl alcohol and anti-caking agent are spray-dried in a spray drying tower according to the weight ratio to obtain tert-ester latex powder; 7) Weigh the prepared tert-ester latex powder, sodium bicarbonate, cellulose ether, and powdered defoamer according to the weight parts, and pour the weighed components into the mixer. There is no requirement for the order of pouring the materials. Stir for 1 to 5 minutes until the mixture is uniform to obtain the powdered interface agent.

6. The application of the powdered interface agent according to claim 1, characterized in that, Powdered interface agents are used in building decoration and renovation structures for interface sealing treatment of concrete or cement-based surfaces, sealing the capillaries of the cement system, and increasing interface adhesion.

7. The application of the powdered interface agent according to claim 6, characterized in that, The application method of powdered interface agent in building decoration and renovation structure includes the following steps: the powdered interface agent is redispersed in clean water with a mixer to form an emulsion, which is then prepared into an aqueous solution of about 10%, with a viscosity of 800-1500 mPa·s and a particle size of 150-300 nm. After stirring into a slurry, it can be applied.

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