CN112029039A - Water-based acrylic emulsion and preparation method thereof - Google Patents
Water-based acrylic emulsion and preparation method thereof Download PDFInfo
- Publication number
- CN112029039A CN112029039A CN202010805860.8A CN202010805860A CN112029039A CN 112029039 A CN112029039 A CN 112029039A CN 202010805860 A CN202010805860 A CN 202010805860A CN 112029039 A CN112029039 A CN 112029039A
- Authority
- CN
- China
- Prior art keywords
- emulsion
- acrylic
- acrylic monomer
- glass transition
- monomer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
- C08F265/04—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00 on to polymers of esters
- C08F265/06—Polymerisation of acrylate or methacrylate esters on to polymers thereof
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D151/00—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
- C09D151/003—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds
Abstract
The application relates to the technical field of coatings, and provides a preparation method of a water-based acrylic emulsion, which comprises the following steps: providing a first pre-emulsion, a second pre-emulsion, and a third pre-emulsion, the first pre-emulsion comprising a first acrylic monomer, the second pre-emulsion comprising a second acrylic monomer, the third pre-emulsion comprising a third acrylic monomer, the glass transition temperature of the polymer formed from the first acrylic monomer being greater than the glass transition temperature of the polymer formed from the third acrylic monomer, and the glass transition temperature of the polymer formed from the third acrylic monomer being greater than the glass transition temperature of the polymer formed from the second acrylic monomer; providing a seed emulsion, dripping the first pre-emulsion into the seed emulsion, and carrying out a first polymerization reaction to obtain a first emulsion; dripping the second pre-emulsion into the first emulsion and carrying out a second polymerization reaction to obtain a second emulsion; and (3) dripping the third pre-emulsion into the second emulsion for a third polymerization reaction, and then adjusting the pH value of the emulsion to be alkaline to obtain the water-based acrylic emulsion.
Description
Technical Field
The application belongs to the technical field of coatings, and particularly relates to a water-based acrylic emulsion and a preparation method thereof.
Background
The water-based wood paint is prepared by taking water as a dispersion medium, taking water-based resin as a film forming substance and matching various auxiliaries, is suitable for indoor and outdoor wooden furniture, doors and windows and various wood wallboards, and plays a decorative and protective role. The waterborne wood lacquer comprises baking varnish resin, waterborne acrylic emulsion, waterborne polyurethane dispersoid and the like, and the waterborne acrylic emulsion is popular with consumers in recent years due to the characteristics of low cost, good adhesive force and no influence on the color of wood substrate.
However, since the solvent of the aqueous acrylic paint is mainly water, the latent heat of water is high, the solvent release property is poor, so that the drying speed of the aqueous acrylic emulsion is slow, the adhesion of the early coating is easy to occur, the stacking of the next coating in a short time is not facilitated, and the production efficiency is low. In order to solve this problem, some technicians propose a method for increasing the glass transition temperature of the aqueous acrylic emulsion, which increases the drying speed of the coating by increasing the glass transition temperature of the aqueous acrylic emulsion, however, the higher the glass transition temperature of the aqueous acrylic emulsion, the higher the minimum film-forming temperature of the aqueous acrylic emulsion, the poorer the film-forming property at room temperature, the larger the amount of the film-forming assistant is required, and the VOC content of the aqueous emulsion is increased to a certain extent, and the environmental protection property of the aqueous emulsion is reduced.
Disclosure of Invention
The application aims to provide a water-based acrylic emulsion and a preparation method thereof, and aims to solve the problems of low drying speed, poor early-stage anti-adhesion property and poor film forming property of the existing water-based acrylic emulsion.
In order to achieve the purpose of the application, the technical scheme adopted by the application is as follows:
in a first aspect, the present application provides a method for preparing an aqueous acrylic emulsion, comprising the steps of:
providing a first pre-emulsion, a second pre-emulsion, and a third pre-emulsion, the first pre-emulsion comprising a first acrylic monomer, the second pre-emulsion comprising a second acrylic monomer, the third pre-emulsion comprising a third acrylic monomer, the glass transition temperature of the polymer formed from the first acrylic monomer being greater than the glass transition temperature of the polymer formed from the third acrylic monomer, and the glass transition temperature of the polymer formed from the third acrylic monomer being greater than the glass transition temperature of the polymer formed from the second acrylic monomer;
providing a seed emulsion, and dripping the first pre-emulsion into the seed emulsion for a first polymerization reaction to obtain a first emulsion;
dripping the second pre-emulsion into the first emulsion and carrying out a second polymerization reaction to obtain a second emulsion;
and dripping the third pre-emulsion into the second emulsion for a third polymerization reaction, and then adjusting the pH value of the emulsion to be alkaline to obtain the water-based acrylic emulsion.
In a second aspect, the present application provides a water-based acrylic emulsion prepared by the above preparation method, wherein the water-based acrylic emulsion comprises latex particles, and the latex particles comprise: the high-glass-transition-temperature shell coats the rubber core, the low-glass-transition-temperature shell coats the high-glass-transition-temperature shell, and the medium-glass-transition-temperature shell coats the low-glass-transition-temperature shell.
The preparation method of the water-based acrylic emulsion provided by the first aspect of the application utilizes three acrylic monomers with different glass transition temperatures as polymerization monomers and adopts a seed emulsion polymerization process, and pre-emulsions respectively containing a first acrylic monomer, a second acrylic monomer and a third acrylic monomer are sequentially dripped into the seed emulsion for polymerization reaction, so as to prepare the water-based acrylic emulsion with dispersed core-shell structure emulsion particles, and the glass transition temperatures of polymers respectively formed by the first acrylic monomer, the third acrylic monomer and the second acrylic monomer are sequentially reduced, so that the shell layers of the emulsion particles comprise a high glass transition temperature shell layer, a low glass transition temperature shell layer and a medium glass transition temperature shell layer which are sequentially arranged from the core to the outside, the high glass transition temperature shell layer has the characteristics of high hardness and quick drying, and the low glass transition temperature shell layer has good film forming property, the medium vitrification temperature shell layer is used as a protective layer of the low vitrification temperature shell layer, the surface anti-adhesion property of the aqueous emulsion is improved, and meanwhile, the drying rate and the film forming property are good.
The water-based acrylic emulsion provided by the second aspect of the application is prepared by the preparation method, and the emulsion particles of the water-based acrylic emulsion comprise shell layers formed by sequentially coating rubber cores by a high glass transition temperature shell layer, a low glass transition temperature shell layer and a medium glass transition temperature shell layer, so that the water-based acrylic emulsion is endowed with good drying rate, early anti-adhesion property and film-forming property.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
In this application, the term "and/or" describes an association relationship of associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a is present alone, A and B are present simultaneously, and B is present alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.
In this application, "at least one" means one or more, for example, "at least one of a, b, or c," or "at least one of a, b, and c," each of which may mean: a. b, c, a-b (i.e. a and b), a-c, b-c or a-b-c, wherein a, b and c can be respectively a single kind or a plurality kinds.
It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
The weight of the related components mentioned in the description of the embodiments of the present application may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the content of the related components is scaled up or down within the scope disclosed in the description of the embodiments of the present application as long as it is scaled up or down according to the description of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application may be a mass unit known in the chemical industry field such as μ g, mg, g, kg, etc.
The terms "first", "second", "third" are used for descriptive purposes only and are used for distinguishing purposes such as substances from one another, and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated, a feature defined as "first", "second", "third" may explicitly or implicitly include one or more such features.
The application provides a preparation method of a water-based acrylic emulsion, which comprises the following steps:
s01, providing a first pre-emulsion, a second pre-emulsion, and a third pre-emulsion, the first pre-emulsion comprising a first acrylic acid monomer, the second pre-emulsion comprising a second acrylic acid monomer, the third pre-emulsion comprising a third acrylic acid monomer, the glass transition temperature of the polymer formed from the first acrylic acid monomer being greater than the glass transition temperature of the polymer formed from the third acrylic acid monomer, and the glass transition temperature of the polymer formed from the third acrylic acid monomer being greater than the glass transition temperature of the polymer formed from the second acrylic acid monomer;
s02, providing a seed emulsion, and dripping the first pre-emulsion into the seed emulsion for a first polymerization reaction to obtain a first emulsion;
s03, dripping the second pre-emulsion into the first emulsion and carrying out a second polymerization reaction to obtain a second emulsion;
s04, dropping the third pre-emulsion into the second emulsion for a third polymerization reaction, and then adjusting the pH value of the emulsion to be alkaline to obtain the water-based acrylic emulsion.
The preparation method of the water-based acrylic emulsion provided by the embodiment of the application utilizes three acrylic monomers with different glass transition temperatures as polymerization monomers and adopts a seed emulsion polymerization process, and pre-emulsions respectively containing a first acrylic monomer, a second acrylic monomer and a third acrylic monomer are sequentially dripped into the seed emulsion for polymerization reaction, so that the water-based acrylic emulsion with dispersed core-shell structure emulsion particles is prepared, and the glass transition temperatures of polymers respectively formed by the first acrylic monomer, the third acrylic monomer and the second acrylic monomer are sequentially reduced, so that the shell layers of the emulsion particles comprise a high glass transition temperature shell layer, a low glass transition temperature shell layer and a medium glass transition temperature shell layer which are sequentially arranged from the core to the outside, the high glass transition temperature shell layer has the characteristics of high hardness and quick drying, and the low glass transition temperature shell layer has good film forming property, the medium vitrification temperature shell layer is used as a protective layer of the low vitrification temperature shell layer, the surface anti-adhesion property of the aqueous emulsion is improved, and meanwhile, the drying rate and the film forming property are good.
Compared with the method for improving the drying speed of the coating by improving the glass transition temperature of the aqueous acrylic emulsion, the method provided by the embodiment of the application effectively improves the drying speed, the early anti-blocking property and the film forming property of the emulsion on the basis of avoiding introducing excessive film forming additives into the emulsion, and provides the aqueous acrylic emulsion with low VOC and high environmental protection.
Specifically, in step S01, the first pre-emulsion comprises a first acrylic acid monomer, the second pre-emulsion comprises a second acrylic acid monomer, and the third pre-emulsion comprises a third acrylic acid monomer, so as to provide a polymerized monomer for the subsequent preparation of the aqueous acrylic emulsion by the seeded emulsion polymerization method.
In the embodiment of the present application, the glass transition temperature of the polymer formed by the first acrylic monomer is higher than that of the polymer formed by the third acrylic monomer, and the glass transition temperature of the polymer formed by the third acrylic monomer is higher than that of the polymer formed by the second acrylic monomer, by using a plurality of acrylic monomers with different glass transition temperatures as polymerization monomers, an aqueous acrylic emulsion having a core-shell structure latex particle is formed, and the glass transition temperature of the shell layer of the latex particle is made to be high, low and medium glass transition temperatures in sequence in the direction from the latex core, so that the shell layer of the latex particle is made up of high-low-medium glass transition temperature shell layers in sequence in the direction from the latex core to the outside.
In some embodiments, the glass transition temperature of the polymer formed from the first acrylic monomer is greater than or equal to 80 ℃, the glass transition temperature of the polymer formed from the second acrylic monomer is less than or equal to 0 ℃, and the glass transition temperature of the polymer formed from the third acrylic monomer is greater than or equal to 30 ℃ and less than or equal to 60 ℃. Therefore, the first acrylic monomer correspondingly forms a shell layer with high glass transition temperature, the drying speed is high, the hardness is high, and the drying speed of the aqueous acrylic emulsion is improved to a certain extent; the second acrylic acid monomer correspondingly forms a low glass transition temperature shell layer, the lowest film forming temperature is low, and the film forming property is good; the third acrylic acid monomer correspondingly forms a medium vitrification temperature shell layer, which has moderate drying rate and hardness and good film forming property, can be used as a protective layer of a low vitrification temperature shell layer to make up the defects of slow drying and poor early anti-adhesion property of the low vitrification temperature shell layer, and has good drying speed and hardness relative to the low vitrification temperature shell layer, so that the shell layer of the latex particle is equivalent to two hard film layers which are connected by a rubber layer, the hardness and the mobility of the latex particle are effectively adjusted, the lowest film forming temperature of the latex particle is reduced, and the film forming property of the emulsion is effectively improved while the drying rate and the surface anti-adhesion property of the water-based acrylic emulsion are improved. In specific examples, the first acrylic monomer has a vitrification temperature of 80 ℃, 83 ℃, 85 ℃, 87 ℃, 91 ℃, 94 ℃, 97 ℃, 99 ℃, 103 ℃, 106 ℃, 109 ℃ or 110 ℃, the second acrylic monomer has a vitrification temperature of 0 ℃, -3 ℃, -5 ℃, -8 ℃, -10 ℃, -13 ℃, -16 ℃, -19 ℃, -21 ℃, -23 ℃, -25 ℃, -27 ℃ or-30 ℃, and the third acrylic monomer has a vitrification temperature of 30 ℃, 34 ℃, 35 ℃, 38 ℃, 41 ℃, 43 ℃, 45 ℃, 47 ℃, 50 ℃, 52 ℃, 56 ℃, 59 ℃ or 60 ℃.
If the polymerized monomer of the embodiment of the present application only uses the second acrylic acid monomer, although the problem of poor film forming property of the existing high glass transition temperature emulsion can be solved, the drying rate is slow, and the surface early anti-adhesion property is poor; if the shell layers of the emulsion particles formed in the embodiment of the application are composed of three types of high-medium-low glass transition temperature shell layers in sequence from the rubber core to the outside, the problem of poor early-stage anti-adhesion property of the emulsion cannot be solved; if the shell layer of the latex particle formed in the embodiment of the application is composed of three types of glass transition temperature shell layers of low-medium-high or medium-low-high in sequence from the rubber core to the outside, the problem of poor film forming property of the emulsion can not be effectively solved.
The kind of the specific acrylic monomer used for the first acrylic monomer, the second acrylic monomer and the third acrylic monomer may refer to the conventional acrylic monomer in the art, so that the glass transition temperature of each monomer meets the above requirements. In some embodiments, the first acrylic monomer, the second acrylic monomer, and the third acrylic monomer are each independently selected from at least one of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobornyl acrylate, isobornyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, isooctyl acrylate, methacrylic acid, acrylic acid, cyclohexyl acrylate, tetrahydrofurfuryl methacrylate, and benzyl methacrylate. The latex particles formed by polymerizing the acrylic monomers have certain hardness and good mobility, and are favorable for further reducing the lowest film-forming temperature of the emulsion. The acrylic monomers listed above are freely combined and the calculated value of the glass transition temperature of the polymer formed therefrom is made to meet the above requirements.
The specific compositions of the first pre-emulsion, the second pre-emulsion and the third pre-emulsion and the preparation method thereof can refer to the conventional techniques in the field. The preemulsion conventionally used in seeded emulsion polymerization is usually composed of polymerized monomers, emulsifiers and water, and sometimes initiators, to promote polymerization of the polymerized monomers. The types of the polymerization monomers, the emulsifier and the initiator in the pre-emulsion should correspond to the system for synthesizing the seed emulsion so as to better initiate the growth of the shell polymer on the basis of the gum nucleus formed by the seed emulsion.
In some embodiments, the first pre-emulsion, the second pre-emulsion, and the third pre-emulsion further comprise an initiator or an initiator and an emulsifier; wherein the initiator is selected from at least one of sodium persulfate, potassium persulfate and ammonium persulfate; the emulsifier is at least one selected from fatty alcohol sulfate, vinyl sulfonate and polyoxyethylene lauryl ether. And respectively adding an initiator into the first pre-emulsion, the second pre-emulsion and the third pre-emulsion to serve as auxiliary initiators, and improving the polymerization effect by the synergistic effect of the auxiliary initiators and the main initiator in the seed emulsion in the polymerization reaction.
In a specific embodiment, the first pre-emulsion comprises 120-135 parts by weight of a first acrylic monomer, 1.8-2.6 parts by weight of an emulsifier, 0.3-0.4 part by weight of an initiator and 50-60 parts by weight of water; the second pre-emulsion consists of 180 weight portions of second acrylic acid monomer 160-180 weight portions, emulsifier 2-3.2 weight portions, initiator 0.4-0.5 weight portion and water 60-80 weight portions; the third pre-emulsion consists of 135 weight portions of 110-135 weight portions of third acrylic acid monomer, 1.8-2.4 weight portions of emulsifier, 0.4 weight portion of initiator and 55-65 weight portions of water.
In step S02, the first pre-emulsion is dropped into the seed emulsion and a first polymerization reaction is performed to form a high glass transition temperature shell.
In the process of carrying out the first polymerization reaction, the seed emulsion is used as the basis of shell layer growth, and the emulsion particles preliminarily formed in the seed emulsion are used as the glue nucleus for forming the shell layer. The specific step of dropping the first pre-emulsion into the seed emulsion and performing the first polymerization reaction may refer to conventional operations in the art, for example, controlling the extent of polymerization by controlling the dropping speed of the first pre-emulsion and the reaction temperature.
In some embodiments, the first pre-emulsion is dripped into the seed emulsion within 60 to 90 minutes at 75 to 95 ℃, and the temperature is kept for reaction for 25 to 60 minutes.
The composition of the seed emulsion may be the same as the composition of the high glass transition temperature shell, the low glass transition temperature shell or the medium glass transition temperature shell.
In some embodiments, the method of preparing a seed emulsion comprises:
s021, providing a bottom material, wherein the bottom material comprises an emulsifier, an initiator, a buffering agent and water;
s022, reacting the base material with part of the first pre-emulsion, the second pre-emulsion or the third pre-emulsion to obtain a seed emulsion.
The primer reacts with part of the first pre-emulsion, the second pre-emulsion or the third pre-emulsion, so that the composition of the latex particle glue core formed by the subsequent reaction is the same as that of the shell with high glass transition temperature, the shell with low glass transition temperature or the shell with medium glass transition temperature, and the reaction is simplified.
Wherein, the buffering agent in step S021 does not participate in the polymerization reaction, and is used for stabilizing the pH environment of the system, so that the reaction is smoothly carried out. The buffer may be classified according to the conventional art, and in some embodiments, the buffer is selected from at least one of sodium bicarbonate, sodium citrate, and sodium dihydrogen phosphate.
In step S022, the specific conditions for reacting the primer with part of the first pre-emulsion, the second pre-emulsion, or the third pre-emulsion can be flexibly adjusted according to the composition of the reaction system. In some embodiments, the primer is mixed with a portion of the first pre-emulsion, the second pre-emulsion, or the third pre-emulsion at a temperature of 75 ℃ to 95 ℃ and the reaction is incubated for at least 20 minutes after the reaction has started (e.g., blue light has appeared). In a specific embodiment, the first pre-emulsion, the second pre-emulsion, or the third pre-emulsion mixed with the base material is 4% to 6% of the amount of the original pre-emulsion.
In step S03, the second pre-emulsion is dropped into the first emulsion and a second polymerization reaction is performed to grow a low glass transition temperature shell on the surface of the high glass transition temperature shell.
The specific step of dropping the second pre-emulsion into the first emulsion and performing the second polymerization reaction may refer to conventional operations in the art, for example, controlling the extent of polymerization by controlling the dropping speed of the second pre-emulsion and the reaction temperature. In some embodiments, the second pre-emulsion is dripped into the first emulsion within a period of 60 to 90 minutes at a temperature of 75 to 95 ℃, and the temperature is maintained for reaction for 25 to 60 minutes.
In step S04, the third pre-emulsion is dropped into the second emulsion and a third polymerization reaction is performed to grow a medium glass temperature shell on the surface of the low glass temperature shell, and after the reaction is completed, the pH of the emulsion is adjusted to be alkaline, thereby obtaining the aqueous acrylic emulsion.
The specific step of dropping the third pre-emulsion into the second emulsion and performing the third polymerization reaction may refer to the conventional operations in the art, for example, controlling the dropping speed of the third pre-emulsion and the reaction temperature to control the polymerization degree. In some embodiments, the third pre-emulsion is dripped into the second emulsion within 60 to 90 minutes at 75 to 95 ℃, and the temperature is maintained for reaction for 25 to 60 minutes.
In some embodiments, the step of adjusting the pH of the emulsion to alkaline comprises: the pH value of the emulsion is adjusted to 7-9, and when the pH value is less than 7, the stability of the emulsion is poor; when the pH is more than 9, the viscosity and smell of the emulsion become excessive. In a further embodiment, the pH value of the emulsion is adjusted to be alkaline by using a neutralizing agent, and the neutralizing agent is selected from at least one of ammonia water, triethylamine, dimethylethanolamine, potassium hydroxide and sodium hydroxide.
On the basis of the embodiment, a crosslinking monomer can be added into a system for synthesizing the water-based acrylic emulsion, so that the crosslinking monomers are crosslinked and polymerized to form a network structure after the emulsion is formed into a film, and the early anti-adhesion property of the water-based acrylic emulsion coating is further improved.
In some embodiments, the third pre-emulsion further comprises a first crosslinking monomer, and further comprises, after the step of adjusting the pH of the emulsion to alkaline: adding a second crosslinking monomer; wherein the first crosslinking monomer is selected from diacetone acrylamide or acetoacetoxyethyl methacrylate, and the second crosslinking monomer is selected from oxalic dihydrazide or ethylenediamine.
The amount of the first crosslinking monomer and the second crosslinking monomer may be flexibly adjusted according to the properties required for the coating, and in some embodiments, the amount of the first crosslinking monomer and the second crosslinking monomer is 0.5 to 10 parts based on 30 to 55 parts by weight of the total amount of the first acrylic monomer, the second acrylic monomer and the third acrylic monomer. By controlling the amount of the crosslinking monomer within the above range, a paint film having good crosslinking density and blocking resistance is ensured, and when the amount of the crosslinking monomer is more than 10 parts, the cost is too high, and slag is easily discharged during the production process.
On the basis of the above embodiment, the method further comprises the following steps after the step of adjusting the pH value of the emulsion to be alkaline: the method also comprises the following steps after the step of adjusting the pH value of the emulsion to be alkaline: and adding an auxiliary agent, wherein the auxiliary agent comprises a defoaming agent and/or a preservative, so that the construction and the packaging of the aqueous acrylic emulsion prepared by the embodiment are convenient, and the long-term storage is ensured without odor.
The specific operations of the step of adding the crosslinking monomer and the step of adding the crosslinking monomer can refer to the routine operations in the field, and in some embodiments, the crosslinking monomer and/or the auxiliary agent are added to the emulsion at 40 ℃ to 50 ℃ and stirred until the mixture is uniformly mixed, for example, 30 minutes.
In the preparation method provided in the examples of the present application, the total amount of the first, second and third acrylic monomers, and the amount of the emulsifier, initiator, buffer, neutralizer and water may be referred to a conventional method for synthesizing an aqueous acrylic emulsion by a seed emulsion polymerization method.
In some embodiments, the preparation raw material of the aqueous acrylic emulsion comprises the following components in parts by weight, based on 100 parts by weight of the total weight of the preparation raw material:
in summary, according to the method provided by the embodiment of the application, acrylic monomers with different glass transition temperatures are used as polymerization monomers, and a seeded emulsion polymerization method is adopted to prepare the aqueous acrylic emulsion, so that the shell layers of the emulsion particles in the emulsion are sequentially composed of three types of high-low-medium glass transition temperature shell layers from the rubber core to the outside, the drying rate, the early anti-adhesion property and the film forming property of the aqueous acrylic emulsion are effectively balanced, meanwhile, a crosslinking monomer is added into the third pre-emulsion and the crosslinking monomer is added into the emulsion after the third polymerization reaction is finished, the early anti-adhesion property of the aqueous acrylic emulsion coating is further improved, the next coating can be stacked in a short time after the aqueous acrylic emulsion coating is formed, and the production efficiency is greatly improved.
On the basis of the preparation method of the water-based acrylic emulsion, the embodiment of the application also provides the water-based acrylic emulsion, which is prepared by the preparation method, wherein the water-based acrylic emulsion comprises emulsion particles, and the emulsion particles comprise: the high-glass-transition-temperature shell covers the gel core, the low-glass-transition-temperature shell covers the high-glass-transition-temperature shell, and the medium-glass-transition-temperature shell covers the low-glass-transition-temperature shell.
The aqueous acrylic emulsion provided by the embodiment of the application is prepared by the preparation method, and the emulsion particles of the aqueous acrylic emulsion comprise shell layers formed by sequentially coating rubber cores by a high-glass-transition-temperature shell layer, a low-glass-transition-temperature shell layer and a medium-glass-transition-temperature shell layer, so that the aqueous acrylic emulsion is endowed with good drying rate, early anti-adhesion property and film-forming property.
In some embodiments, the glue core has the same composition as the high glass transition temperature shell, the low glass transition temperature shell, or the medium glass transition temperature shell.
The practice of the present invention is illustrated by the following examples.
Example 1
The embodiment provides a water-based acrylic emulsion, and the preparation method comprises the following steps:
(1) pre-emulsification
In an emulsifying kettle, adding 1.8g of sodium dodecyl sulfate and 0.3g of sodium persulfate into the emulsifying kettle containing 50g of deionized water, then sequentially adding 100g of methyl methacrylate and 20g of butyl methacrylate into the emulsifying kettle in a high-speed dispersion state, and carrying out high-speed emulsification and stirring for 30min to form a first pre-emulsion;
in an emulsifying kettle, adding 2g of sodium dodecyl sulfate and 0.4g of sodium persulfate into the emulsifying kettle containing 60g of deionized water, then sequentially adding 58g of methyl methacrylate, 100g of butyl acrylate and 2g of methacrylic acid into the emulsifying kettle in a high-speed dispersion state, and emulsifying and stirring at a high speed for 30min to form a second pre-emulsion;
in an emulsifying kettle, adding 1.8g of sodium dodecyl sulfate and 0.4g of sodium persulfate into the emulsifying kettle containing 55g of deionized water, adding 10g of diacetone acrylamide for dissolution, sequentially adding 4g of methacrylic acid, 80g of cyclohexyl acrylate and 26g of methyl methacrylate into the emulsifying kettle in a high-speed dispersion state, and carrying out high-speed emulsification and stirring for 30min to form a third pre-emulsion;
(2) seed emulsion polymerization
Sequentially adding 2.5g of lauryl sodium sulfate, 1g of sodium bicarbonate, 0.5g of sodium persulfate and 280g of deionized water into a 1000mL four-neck flask provided with a stirring device and a thermometer, and stirring to form a bottom material; heating to 85 ℃, adding 5% of the first pre-emulsion prepared in the step (1) into a reaction kettle, and preserving heat for 20 minutes after blue light appears to form seed emulsion;
keeping the temperature, dropwise adding the rest first pre-emulsion prepared in the step (1) into the seed emulsion for 60 minutes, and keeping the temperature for 30 minutes after dropwise adding to form a first emulsion;
keeping the temperature, dropwise adding the second pre-emulsion into the first emulsion for 90 minutes, and keeping the temperature for 30 minutes after dropwise adding to form a second emulsion;
and keeping the temperature, dropwise adding the third pre-emulsion into the second emulsion for 60 minutes, keeping the temperature for 30 minutes after dropwise adding, then cooling to 45 ℃, adding 5g of ammonia water into the reaction kettle to adjust the pH value of the emulsion to 7-8, then continuously adding 5g of adipic acid dihydrazide (a solution formed by dissolving the adipic acid dihydrazide in 40g of deionized water) and auxiliary agents such as a defoaming agent and a preservative which need to be added, and stirring for 30 minutes to obtain the aqueous acrylic emulsion.
Example 2
The embodiment provides a water-based acrylic emulsion, and the preparation method comprises the following steps:
(1) pre-emulsification
In an emulsifying kettle, 2.6g of JS-2 (vinyl sulfonate) and 0.4g of ammonium persulfate are added into the emulsifying kettle containing 60g of deionized water, then 113g of methyl methacrylate, 20g of isobornyl methacrylate and 2g of acrylic acid are sequentially added into the emulsifying kettle in a high-speed dispersion state, and the high-speed emulsification and the stirring are carried out for 30min to form a first pre-emulsion;
in an emulsifying kettle, 3.2g of JS-2 (vinyl sulfonate) and 0.5g of ammonium persulfate are added into the emulsifying kettle containing 80g of deionized water, then 56g of methyl methacrylate, 120g of isooctyl acrylate and 4g of methacrylic acid are sequentially added into the emulsifying kettle in a high-speed dispersion state, and the mixture is emulsified and stirred at a high speed for 30min to form a second pre-emulsion;
in an emulsifying kettle, 2.4g of JS-2 (vinyl sulfonate) and 0.4g of ammonium persulfate are added into the emulsifying kettle containing 65g of deionized water, 10g of diacetone acrylamide is added and dissolved, then 6g of methacrylic acid, 60g of tert-butyl acrylate and 69g of butyl methacrylate are sequentially added into the emulsifying kettle in a high-speed dispersion state, and high-speed emulsification and stirring are carried out for 30min to form a third pre-emulsion;
(2) seed emulsion polymerization
6.5g of JS-2 (vinylsulfonate), 1.5g of sodium bicarbonate, 0.6g of ammonium persulfate and 240g of deionized water are sequentially added into a 1000mL four-neck flask provided with a stirring device and a thermometer, and stirred to form a bottom material; heating to 85 ℃, adding 8% of the first pre-emulsion prepared in the step (1) into a reaction kettle, and preserving heat for 20 minutes after blue light appears to form seed emulsion;
keeping the temperature, dropwise adding the rest first pre-emulsion prepared in the step (1) into the seed emulsion for 60 minutes, and keeping the temperature for 30 minutes after dropwise adding to form a first emulsion;
keeping the temperature, dropwise adding the second pre-emulsion into the first emulsion for 90 minutes, and keeping the temperature for 30 minutes after dropwise adding to form a second emulsion;
and keeping the temperature, dropwise adding the third pre-emulsion into the second emulsion for 60 minutes, keeping the temperature for 60 minutes after dropwise adding, then cooling to 45 ℃, adding 6g of ammonia water into the reaction kettle to adjust the pH value of the emulsion to 7-8, then continuously adding 5g of adipic acid dihydrazide (a solution formed by dissolving the adipic acid dihydrazide in 40g of deionized water) and auxiliary agents such as a defoaming agent and a preservative which need to be added, and stirring for 30 minutes to obtain the aqueous acrylic emulsion.
Comparative example 1
The comparative example provides a water-based acrylic emulsion, the preparation method of which comprises the following steps:
(1) pre-emulsification
In an emulsifying kettle, 2g of sodium dodecyl sulfate and 0.3g of sodium persulfate are added into the emulsifying kettle containing 60g of deionized water, then 200g of methyl methacrylate and 50g of butyl methacrylate are sequentially added into the emulsifying kettle in a high-speed dispersion state, and the high-speed emulsification and the stirring are carried out for 30min to form a first pre-emulsion.
In an emulsifying kettle, 2g of sodium dodecyl sulfate and 0.4g of sodium persulfate are added into the emulsifying kettle containing 60g of deionized water, then 80g of methyl methacrylate, 110g of butyl acrylate, 6g of diacetone acrylamide and 4g of methacrylic acid are sequentially added into the emulsifying kettle in a high-speed dispersion state, and the second pre-emulsion is formed by high-speed emulsification and stirring for 30 min.
(2) Seed emulsion polymerization
Sequentially adding 3g of sodium dodecyl sulfate, 1g of sodium bicarbonate, 0.5g of sodium persulfate and 280g of deionized water into a 1000mL four-neck flask provided with a stirring device and a thermometer, and stirring to form a bottom material; heating to 85 ℃, adding 5% of the first pre-emulsion prepared in the step (1) into a reaction kettle, and preserving heat for 20 minutes after blue light appears to form seed emulsion;
keeping the temperature, dropwise adding the rest of the first pre-emulsion prepared in the step (1) into the seed emulsion for 60 minutes, keeping the temperature for 30 minutes after dropwise adding, then continuously dropwise adding the second pre-emulsion for 90 minutes, and keeping the temperature for 30 minutes after dropwise adding; then cooling to 45 ℃, adding 5g of ammonia water into the reaction kettle to adjust the pH value of the emulsion to 7-8, then continuously adding 3g of adipic acid dihydrazide (solution dissolved in 40g of deionized water) and auxiliary agents such as a defoaming agent and a preservative which need to be added, and stirring for 30 minutes to obtain the aqueous acrylic emulsion.
The aqueous acrylic emulsion provided in the examples 1-2 and the comparative example 1 and a proper amount of film-forming additive are prepared into aqueous wood primer, and the performance tests are respectively carried out.
The test results are shown in table 1, the lowest amount of the film-forming additive in the wood primer prepared from the aqueous acrylic emulsion of the embodiment 1-2 is lower than that of the comparative example 1, which shows that the VOC of the paint can be reduced by using the aqueous acrylic emulsion of the embodiment, and the paint is green and environment-friendly; meanwhile, the surface drying time, the hardness and the early anti-adhesion property of the wood primer prepared from the water-based acrylic emulsion in the embodiment 1-2 are all superior to those of the wood primer in the comparative example 1, which shows that the surface drying property, the hardness and the early anti-adhesion property of the emulsion can be effectively improved by the method provided by the embodiment of the application.
TABLE 1
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (9)
1. The preparation method of the water-based acrylic emulsion is characterized by comprising the following steps:
providing a first pre-emulsion, a second pre-emulsion, and a third pre-emulsion, the first pre-emulsion comprising a first acrylic monomer, the second pre-emulsion comprising a second acrylic monomer, the third pre-emulsion comprising a third acrylic monomer, the glass transition temperature of the polymer formed from the first acrylic monomer being greater than the glass transition temperature of the polymer formed from the third acrylic monomer, and the glass transition temperature of the polymer formed from the third acrylic monomer being greater than the glass transition temperature of the polymer formed from the second acrylic monomer;
providing a seed emulsion, and dripping the first pre-emulsion into the seed emulsion for a first polymerization reaction to obtain a first emulsion;
dripping the second pre-emulsion into the first emulsion and carrying out a second polymerization reaction to obtain a second emulsion;
and dripping the third pre-emulsion into the second emulsion for a third polymerization reaction, and then adjusting the pH value of the emulsion to be alkaline to obtain the water-based acrylic emulsion.
2. The production method according to claim 1, wherein a glass transition temperature of a polymer formed from the first acrylic monomer is 80 ℃ or higher, a glass transition temperature of a polymer formed from the second acrylic monomer is 0 ℃ or lower, and a glass transition temperature of a polymer formed from the third acrylic monomer is 30 ℃ or higher and 60 ℃ or lower.
3. The production method according to claim 1, wherein the first acrylic monomer, the second acrylic monomer, and the third acrylic monomer are each independently selected from at least one of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobornyl acrylate, isobornyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, isooctyl acrylate, methacrylic acid, acrylic acid, cyclohexyl acrylate, tetrahydrofurfuryl methacrylate, and benzyl methacrylate.
4. The method of claim 1, wherein the third pre-emulsion further comprises a first cross-linking monomer, and further comprising, after the step of adjusting the pH of the emulsion to alkaline: adding a second crosslinking monomer;
wherein the first crosslinking monomer is selected from diacetone acrylamide or acetoacetoxyethyl methacrylate, and the second crosslinking monomer is selected from oxalic dihydrazide or ethylenediamine.
5. The preparation method according to claim 1, wherein the first pre-emulsion is dripped into the seed emulsion within 60 to 90 minutes at 75 to 95 ℃, and the temperature is kept for 25 to 60 minutes; and/or
Dripping the second pre-emulsion into the first emulsion within 60-90 minutes at 75-95 ℃, and carrying out heat preservation reaction for 25-60 minutes; and/or
And dripping the third pre-emulsion into the second emulsion within 60-90 minutes at 75-95 ℃, and carrying out heat preservation reaction for 25-60 minutes.
6. The method of any one of claims 1 to 5, wherein the seed emulsion is prepared by a method comprising:
providing a primer, wherein the primer comprises an emulsifier, an initiator, a buffering agent and water;
and reacting the bottom material with part of the first pre-emulsion, the second pre-emulsion or the third pre-emulsion to obtain the seed emulsion.
7. The method according to claim 6, wherein the first pre-emulsion, the second pre-emulsion, and the third pre-emulsion further contain the initiator or the initiator and the emulsifier;
wherein the initiator is selected from at least one of sodium persulfate, potassium persulfate and ammonium persulfate;
the emulsifier is at least one selected from fatty alcohol sulfate, vinyl sulfonate and polyoxyethylene lauryl ether.
8. The method according to any one of claims 1 to 5, wherein the step of adjusting the pH of the emulsion to be alkaline comprises: adjusting the pH of the emulsion to 7-9; and/or
The method also comprises the following steps after the step of adjusting the pH value of the emulsion to be alkaline: and adding an auxiliary agent, wherein the auxiliary agent comprises a defoaming agent and/or a preservative.
9. An aqueous acrylic emulsion prepared by the method of any one of claims 1 to 8, comprising emulsion particles comprising: the high-glass-transition-temperature shell coats the rubber core, the low-glass-transition-temperature shell coats the high-glass-transition-temperature shell, and the medium-glass-transition-temperature shell coats the low-glass-transition-temperature shell.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010805860.8A CN112029039B (en) | 2020-08-12 | 2020-08-12 | Water-based acrylic emulsion and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010805860.8A CN112029039B (en) | 2020-08-12 | 2020-08-12 | Water-based acrylic emulsion and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112029039A true CN112029039A (en) | 2020-12-04 |
| CN112029039B CN112029039B (en) | 2022-10-21 |
Family
ID=73577840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010805860.8A Active CN112029039B (en) | 2020-08-12 | 2020-08-12 | Water-based acrylic emulsion and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112029039B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115353591A (en) * | 2022-08-31 | 2022-11-18 | 科顺防水科技股份有限公司 | Method for preparing emulsion for JS waterproof coating, emulsion for JS waterproof coating and two-component JS waterproof coating |
| CN116003675A (en) * | 2022-12-09 | 2023-04-25 | 万华化学集团股份有限公司 | Acrylic emulsion for blood compatibility coating and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4515914A (en) * | 1983-10-19 | 1985-05-07 | The Dow Chemical Company | Crosslinked latexes encapsulated with linear polymers |
| CN102199239A (en) * | 2010-03-24 | 2011-09-28 | 东莞大宝化工制品有限公司 | Preparation method for acrylic acid microemulsion with self-crosslinking core-shell structure |
| CN102827322A (en) * | 2012-08-14 | 2012-12-19 | 华南理工大学 | Preparation method and application of internal-external dual cross-linked core-shell structured acrylic acid emulsion |
| CN105722876A (en) * | 2013-11-15 | 2016-06-29 | 阿科玛法国公司 | Aqueous dispersion of polymer made from multistructured particles for aqueous wall coatings resistant to dirt and wet abrasion |
| CN106866869A (en) * | 2017-02-23 | 2017-06-20 | 同光（江苏）新材料科技有限公司 | A kind of preparation method of core shell structure hydroxyl acrylic emulsion |
| CN109280123A (en) * | 2018-10-25 | 2019-01-29 | 东莞大宝化工制品有限公司 | Acrylic acid ester emulsion and preparation method thereof |
| CN111116831A (en) * | 2020-01-07 | 2020-05-08 | 黄禹 | Preparation method of hydroxyl acrylic emulsion |
-
2020
- 2020-08-12 CN CN202010805860.8A patent/CN112029039B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4515914A (en) * | 1983-10-19 | 1985-05-07 | The Dow Chemical Company | Crosslinked latexes encapsulated with linear polymers |
| CN102199239A (en) * | 2010-03-24 | 2011-09-28 | 东莞大宝化工制品有限公司 | Preparation method for acrylic acid microemulsion with self-crosslinking core-shell structure |
| CN102827322A (en) * | 2012-08-14 | 2012-12-19 | 华南理工大学 | Preparation method and application of internal-external dual cross-linked core-shell structured acrylic acid emulsion |
| CN105722876A (en) * | 2013-11-15 | 2016-06-29 | 阿科玛法国公司 | Aqueous dispersion of polymer made from multistructured particles for aqueous wall coatings resistant to dirt and wet abrasion |
| CN106866869A (en) * | 2017-02-23 | 2017-06-20 | 同光（江苏）新材料科技有限公司 | A kind of preparation method of core shell structure hydroxyl acrylic emulsion |
| CN109280123A (en) * | 2018-10-25 | 2019-01-29 | 东莞大宝化工制品有限公司 | Acrylic acid ester emulsion and preparation method thereof |
| CN111116831A (en) * | 2020-01-07 | 2020-05-08 | 黄禹 | Preparation method of hydroxyl acrylic emulsion |
Non-Patent Citations (4)
| Title |
|---|
| 崔嘉敏等: "成膜助剂在多层核/壳丙烯酸酯乳液中的应用", 《涂料工业》, no. 10, 1 October 2008 (2008-10-01), pages 19 - 22 * |
| 张心亚等: "梯度乳液聚合制备核壳结构丙烯酸酯乳液――合成工艺", 《湖南师范大学自然科学学报》, no. 04, 25 December 2006 (2006-12-25), pages 62 - 67 * |
| 张心亚等: "梯度乳液聚合制备核壳结构丙烯酸酯乳液――性能表征", 《湖南师范大学自然科学学报》, no. 03, 30 September 2007 (2007-09-30), pages 71 - 74 * |
| 李喜兰等: "一种新型丙烯酸乳液的研制", 《合成材料老化与应用》, no. 01, 15 March 2007 (2007-03-15), pages 23 - 26 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115353591A (en) * | 2022-08-31 | 2022-11-18 | 科顺防水科技股份有限公司 | Method for preparing emulsion for JS waterproof coating, emulsion for JS waterproof coating and two-component JS waterproof coating |
| CN115353591B (en) * | 2022-08-31 | 2023-08-04 | 科顺防水科技股份有限公司 | Method for preparing emulsion for JS waterproof paint, emulsion for JS waterproof paint and two-component JS waterproof paint |
| CN116003675A (en) * | 2022-12-09 | 2023-04-25 | 万华化学集团股份有限公司 | Acrylic emulsion for blood compatibility coating and preparation method thereof |
| CN116003675B (en) * | 2022-12-09 | 2024-05-03 | 万华化学集团股份有限公司 | Acrylic emulsion for blood compatibility coating and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112029039B (en) | 2022-10-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4150515B2 (en) | Method for forming an aqueous polymer dispersion | |
| US4894397A (en) | Stable emulsion polymers and methods of preparing same | |
| CN107434842B (en) | Core-shell structure hydroxyl acrylic resin emulsion and preparation method and application thereof | |
| US4740546A (en) | Aqueous dispersion of vinyl copolymer resin | |
| CN112194760B (en) | Polyacrylate emulsion and preparation method thereof | |
| CN112029039B (en) | Water-based acrylic emulsion and preparation method thereof | |
| TWI521004B (en) | Aqueous organic silicon fluoro-containing polymer dispersion and method for manufacturing the same | |
| CN109369839B (en) | Self-crosslinking vinyl chloride copolymer emulsion and preparation method thereof | |
| CN108864376A (en) | Water soluble acrylic resin and preparation method thereof, hydrophilic coating and preparation method thereof | |
| WO2023198148A1 (en) | Waterborne core-shell emulsion for wood substrate | |
| CN113980187B (en) | Water-based matte core-shell emulsion and preparation method and application thereof | |
| CA1339436C (en) | Non-aqueous dispersion for alkyd formulations and method of manufacture | |
| CN110036046B (en) | Method for preparing vinyl chloride-based resin composition | |
| CN112126002B (en) | Water-based acrylic resin, preparation method thereof and amino baking varnish | |
| CN111072845A (en) | Emulsion and method for producing the same | |
| CN115124649B (en) | Real stone paint emulsion and preparation method and application thereof | |
| CN112851882B (en) | Preparation method of epoxy resin modified styrene-acrylic emulsion for plastic ink | |
| TWI764980B (en) | Emulsion and method of preparing the same | |
| JPH0651860B2 (en) | Anti-blocking paint | |
| CN111303333B (en) | Quick-drying water-based acrylic polymer emulsion and preparation method and application thereof | |
| CN112851885B (en) | Single-component self-crosslinking emulsion with hard barrier layer, preparation method and application | |
| CN112708080B (en) | Single-component self-crosslinking emulsion with soft barrier layer, preparation method and application | |
| CN111995710B (en) | Inorganic silicon modified soap-free acrylic emulsion and preparation method thereof | |
| CN109734836B (en) | Acrylate microgel emulsion and preparation method and application thereof | |
| KR100577497B1 (en) | Manufacturing method of phase inverted core / shell microgel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |