KR100927086B1 - Method of preparing hybrid nano particle through seeded emulsion polymerization - Google Patents

Abstract

The present invention relates to a method for producing a composite nanoparticle in which a compound that is thermally decomposed to generate gas and / or free radicals is dispersed in a polymer matrix or phase-separated by forming a core in the polymer shell. Compounds that decompose to generate gases and / or free radicals; Hard water preparation; Preparing a seed particulate miniemulsion containing an emulsifier and an organic solvent; And (b) adding a monomer for forming a polymer to the seed particulate miniemulsion and emulsion-polymerizing the monomer using the seed particulate miniemulsion as a seed. The present invention also provides a composite nanoparticle produced by the above method.

Description

Method for producing composite nanoparticles by seed emulsion polymerization {METHOD OF PREPARING HYBRID NANO PARTICLE THROUGH SEEDED EMULSION POLYMERIZATION}

1 is a graph showing the change in weight according to the temperature of the composite nanoparticles prepared in Example 1.

Figure 2 is a graph showing the weight change with temperature of the composite nanoparticles prepared in Example 2.

The present invention relates to a method for producing composite nanoparticles in which compounds which thermally decompose to generate gas and / or free radicals are dispersed in a polymer matrix or in which a core is formed in a polymer shell to be phase separated.

In general, when a chemical blowing agent is used to make a polymer foam, the necessary blowing agent is usually stored in a powder state, and then used in a chemical reaction process by weighing it according to the required use. For example, when a chemical foaming agent is used for the foaming of PVC, each component is added in the dry mixing step, mixed by mechanical method, and then dispersed on the PVC melt in the extrusion or calender process, and the melt is used for heating the oven. As it passes, the blowing agent decomposes due to heat, and gas is generated to form a foam.

In the case of foaming a polymeric material using a blowing agent, the blowing agent is determined to have uniformity of dispersion according to chemical and physical properties. Therefore, how small particles of blowing agent are used is an important factor in determining the characteristics of the foaming cell. Element. In addition, since the blowing agent is a compound, the components that can be used together have been limited because the compound may be affected by other component compounds, and the use thereof is also limited.

WO 99/002589 discloses a method of confining an organic fluorinated hydrocarbon compound in a cavity inside a polymer particle. The foaming agent-containing particles obtained by this method can be used for heat insulating materials, packaging materials, etc. since the fluorinated hydrocarbons inside them are expanded to increase their volume when heated. However, this method is not a perfect inert gas because the material to be vaporized is an organic fluorinated hydrocarbon, there is a problem that the particle size is limited to a size of several to several tens of micrometers (μm) or more.

In WO 02/096984 and WO 02/096635, an example of preparing and using microparticles in which a hydrocarbon vaporized when heated in a desired temperature range in a polymer particle is collected in a polymer particle in a manner similar to the above is used, but the generated gas It is a combustible material, and the particle size is also several tens of micrometers, so there is a limit to uniform dispersion.

The present invention is to overcome the limitations of the existing products or processes described above, to provide a method for producing a composite nanoparticle protected by thermal decomposition of a compound generating gas and / or free radicals in a polymer matrix or wrapped with a polymer It aims to do it.

In addition, the present invention is to provide a method for producing the composite nanoparticles using a seed emulsion polymerization method using as a seed the liquid fine particles are dissolved thermally decomposed compound generating gas and / or free radicals The purpose.

The present invention provides a method for producing composite nanoparticles in which a compound that thermally decomposes to generate gas and / or free radicals is dispersed in a polymer matrix or phase separated by forming a core in the polymer shell.

(a) a compound that thermally decomposes to generate gas and / or free radicals; Hard water preparation; Preparing a seed particulate miniemulsion containing an emulsifier and an organic solvent; And

(b) adding a monomer for forming a polymer to the seed particulate miniemulsion and emulsifying the monomer using the seed particulate miniemulsion as a seed.

The present invention also provides a composite nanoparticle produced by the above method.

Hereinafter, the present invention will be described in detail.

The composite nanoparticles according to the present invention contain a compound and a polymer which are decomposed by heat to generate gas and / or free radicals.

In this case, the compound generating gas and / or free radicals means a compound generating gas, a compound generating free radical, or a compound generating both gas and free radical.

In addition, the composite nanoparticles according to the present invention are characterized in that the compound which is thermally decomposed to generate gas and / or free radicals is regularly or irregularly dispersed in the polymer matrix or phase separated by forming a core in the polymer shell. That is, the compound that is thermally decomposed to generate gas and / or free radicals is nanoparticles present on the surface or inside of the polymer. Thus, the composite nanoparticles of the present invention are relatively stable with external environmental factors such as other compounds, external temperatures, physical and electrical stimuli, and the like.

The method for producing the composite nanoparticles according to the present invention is characterized by using a seed emulsion polymerization method using, as seeds, liquid fine particles in which a compound which is thermally decomposed to generate gas and / or free radicals is dissolved.

In this way, when the liquid phase material is made into a miniemulsion state and used as seed fine particles, the microemulsified liquid fine particles can function stably as seeds during the polymerization process, thereby producing uniform and stable particles, and producing seed particles. Time and energy can be minimized.

Specifically, the manufacturing method of the composite nanoparticles according to the present invention,

(a) a compound that thermally decomposes to generate gas and / or free radicals; Hard water preparation; Preparing a seed particulate miniemulsion containing an emulsifier and an organic solvent; And

(b) adding a monomer for forming a polymer to the seed particulate miniemulsion, and emulsion-polymerizing the monomer using the seed particulate miniemulsion as a seed.

In the production method according to the invention, the mini-emulsion of step (a),

(Iii) a compound that thermally decomposes to generate gas and / or free radicals; Hard water preparation; And dissolving an emulsifier in an organic solvent to prepare an organic mixed solution.

(Ii) dispersing the organic mixed solution in water to form a preemulsion; And

(Iii) homogenizing the crude oil with a homogenizer to form a mini emulsion.

In addition, the mini-emulsion of step (a) may further contain one or more selected from the group consisting of an initiator for polymerization and a buffer for pH adjustment. In addition, the monomer for forming the polymer of step (b) may be added together with at least one selected from the group consisting of an emulsifier, water and an initiator for polymerization.

The polymerization in the step (b) is preferably polymerized at a temperature lower than the temperature at which the compound generating the gas and / or free radicals is decomposed. When the polymerization is carried out at a high temperature, gas and / or free radicals may be generated by thermal decomposition at the same time as the polymerization reaction, and as a result, the amount of the compound which is thermally decomposed to generate gas and / or free radicals is reduced to a desired amount. It is undesirable because it is not possible to produce composite nanoparticles with a content.

After the step (b), (c) may further comprise the step of removing the organic solvent contained in the polymerization product. The organic solvent may be stripped or evaporated, but is not limited thereto.

Among the materials constituting the organic mixed solution in the manufacturing method of the present invention, the liquid state is to use only the organic material capable of forming a mini emulsion in order to keep the mini emulsion, which is an emulsion using water as a matrix, throughout the whole process. desirable.

Therefore, the liquid state of the materials constituting the organic mixed solution should have a certain degree of hydrophobicity to form a mini-emulsion, so that at 25 ℃ water solubility of 75g / kg or less used alone or mixed It is desirable to. If they have too high solubility in water, they may fail to form stable mini-emulsions, which may cause problems such as the size of the particles growing out of a target range or a coagulum formed during the manufacturing process.

In addition, in the method for producing composite nanoparticles, the mini-emulsion of step (a) is an oil phase dispersed without dissolving in water, in which the compound that thermally decomposes to generate gas and / or free radicals is dissolved at the molecular level. It is composed of a mixture of an organic solvent, a hydrophobic agent and an emulsifier.

At this time, the organic solvent is preferably a boiling point of 60 ~ 150 ℃, preferably 60 ~ 120 ℃, more preferably 60 ~ 100 ℃ so that it can be easily removed after the polymerization is completed. Non-limiting examples of organic solvents include, but are not limited to, toluene, hexane, isooctane, benzene, chloroform, methylisobutyrate, and the like.

In addition, the amount of the organic solvent varies depending on the type of the compound for forming the polymer and the monomer for forming the polymer and the thermal decomposition by dissolving gas and / or free radicals. It is preferably 0.01 to 150 parts by weight, more preferably 0.01 to 100 parts by weight, and may be used alone or in combination of two or more thereof.

In the production method of the present invention, non-limiting examples of compounds that thermally decompose to generate gas include azo compounds, organic peroxides, hydrazide compounds, carbazide compounds, and the like. Silver can be used individually or in mixture of 2 or more types.

Specifically, non-limiting examples of the azo compound include azobisisobutyronitrile (2,2'-Azobis (isobutyronitrile)), azobis (2-methylbutyronitrile) (2,2'-Azobis (2-methylbutyronitrile)), azobis (2-methylvaleronitrile) (2,2'-azobis (2-methylvaleronitrile)), azobis (2,3-dimethylbutyronitrile) (2,2'-azobis (2,3-dimethylbutyronitrile), azobis (2-methylcapronitrile) (2,2'-azobis (2-methylcapronitrile)), azobis (2,4-dimethylvaleronitrile) (2,2'-azobis (2,4-dimethylvaleronitrile)), azobis (1-cyclohexylsaanide) (1,1'-Azobis (1-cyclohexylcyanide), dimethoxyazopropane (2,2'-dimethoxy-2,2'- azopropane), diethoxy azopropane (2,2'-diethoxy-2,2'-azopropane), dipropoxyzopropane (2,2'- dipropoxy-2,2'-azopropane), diisopropoxyzopropane (2,2'-diisopropoxy-2,2'-azopropane), dibutoxy azopropane (2,2'-dibutoxy-2,2'-azopropane), diisobutoxy azopropane (2,2'-diisobuto xy-2,2'-azopropane), dineobutoxy azopropane (2,2'-dineobutoxy-2,2'-azopropane), azodicarbondmide, azobis (N-butyl-2-methyl Propionamide) (2,2'-azobis (N-butyl-2-methylpropionamide)), but is not limited thereto.

Non-limiting examples of the organic peroxides include bis (3-methyl-3-methoxybutyl) peroxydicarbonate, t-butyl peroxy neodecanoate (t -butyl peroxyneodecanoate, t-butyl peroxy pivalate, lauryl peroxide, stearyl peroxide, t-butyl peroxy-2-ethylhexanoate (t-butyl peroxy-2-ethylhexanoate), benzoyl peroxide, t-butyl peroxylaurate, t-butylperoxy 2-ethylhexyl carbonate ), t-butylperoxybenzoate t-hexyl peroxybenzoate (t-hexyl peroxybenzoate), dicumyl peroxide, t-butyl cumylperoxide, di- di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butyl peroxy) hexane (2,5-dimethyl-2,5-b is (t-butyl peroxy) hexane, but is not limited thereto.

Non-limiting examples of the hydrazide compound is benzosulfonylhydrazide, 4,4'-oxybis (benzenesulfonylhydrazide), para P-toluenesulfonylhydrazide, polybenzenesulfonylhydrazide, bis (hydrazosulfonylbenzene), 4,4'-bis (hydrazol) Diphenylsulfone-3,3-disulfonylhydrazide (4,4'-bis (hydrazosulfonyl) biphenyl), diphenyldisulfonylhydrazide, diphenylsulfon-3,3-disulfonylhydrazide Etc., but is not limited thereto.

In addition, non-limiting examples of the carbazide compound include terephthalzide, other fatty acid azide and aromatic acid azide, but are not limited thereto.

In the production method of the present invention, non-limiting examples of a compound that is thermally decomposed to generate free radicals include azo compounds, organic peroxides, and the like, and these compounds may be used alone or in combination of two or more thereof.

The amount of the compound that is thermally decomposed to generate gas and / or free radicals is 5 to 200 parts by weight, preferably 5 to 150 parts by weight, more preferably 5 to 100 parts by weight based on 100 parts by weight of the polymer forming monomer. Can be used. When the amount of the compound used exceeds 200 parts by weight, the compound is bleeded and precipitated in the polymer dispersed after polymerization, thereby reducing the efficiency of protecting the polymer, thus making it difficult to form composite nanoparticles. On the other hand, if the amount is less than 5 parts by weight of the gas and / or free radicals generated by the thermal decomposition is not preferable because the action effect of the generated gas and / or free radicals is small.

In the preparation method according to the invention, the ultrahydrophobe is mixed with other groups of hydrophobic substances (oil phase gas and / or free radicals, and organic solvents) to form a uniform solution. When the emulsifier is mixed into the dissolved water and then the oil phase is dispersed in the water through a homogenizer with tens to hundreds of nm of particles, the organic matter constituting the dispersed oil remains are separated into small particles by the Ostwald ripening principle. It is a material that exerts osmotic pressure, a force that blocks the movement of large particles. In order to satisfy these characteristics, the hydrophobic agent preferably has a solubility in water of 25 ° C. of 5 × 10 ⁻⁶ g / kg or less.

Non-limiting examples of preparative agents include hydrocarbons having 12 to 20 carbon atoms, aliphatic alcohols having 12 to 20 carbon atoms, acrylates having alkyl groups having 12 to 20 carbon atoms, alkyl mercaptans having 12 to 20 carbon atoms, organic materials, fluorinated alkanes, Silicone oil compounds, natural oils or synthetic oils, and the like, these may be used alone or in combination of two or more.

The amount of the hydrophobic agent used may be 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, and more preferably 1.5 to 5 parts by weight based on 100 parts by weight of the organic solvent.

In the production method according to the present invention, the emulsifiers alone or two kinds of anionic emulsifiers, cationic emulsifiers, nonionic emulsifiers, or reactive emulsifiers copolymerizable with monomers for forming polymers, etc. used in conventional emulsion polymerization. It can mix and use the above.

The amount of the emulsifier to be used is determined according to the particle size of the desired finally obtained emulsion, and may be used at 0.05 to 20 parts by weight based on 100 parts by weight of the organic solvent.

In the production method of the present invention, the polymer forming monomer is polymerized with free radicals in the mini-emulsion seed; Water must be insoluble or hydrophilic; Furthermore, even when the half-life of the compound which is thermally decomposed to generate gas and / or free radicals to be mixed together is 10 ° C. or less, preferably 15 ° C. or less, and more preferably 20 ° C. or less, than the decomposition temperature when 10 hours is used. It is preferred to be polymerized, but is not limited thereto.

As the monomer for forming a polymer satisfying these conditions, compounds having an unsaturated double bond, in which a polymerization reaction by free radicals proceed, may be used.

Non-limiting examples of the compound having an unsaturated double bond include (meth) acrylate compounds, (meth) acrylonitrile compounds, (meth) acrylic acid compounds, (meth) acrylamide compounds, styrene compounds, vinyl And a compound such as a lidene chloride, a vinyl halide compound and a butadiene compound. In addition, these can be used individually or in mixture of 2 or more types.

Examples of the (meth) acrylate-based compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and isobutyl (Meth) acrylate, n-hexyl (meth) acrylate, ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (Meth) acrylate, cyclohexyl (meth) acrylate, butylcyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenylethyl (meth) acrylate, phenylpropyl (meth) acrylate, butanediol di (meth) ) Acrylate, ethylene glycol di (meth) acrylate, tripropylene glycol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and the like;

Examples of the (meth) acrylonitrile-based compound include (meth) acrylonitrile;

Examples of the (meth) acrylic acid compound include (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and the like;

Examples of the (meth) acrylamide compound include (meth) acrylamide;

Examples of styrene compounds include styrene, α-methylstyrene, vinyltoluene, p-nitrostyrene, ethylvinylbenzene, divinyl benzene and the like;

Examples of butadiene compounds include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, but are not limited thereto.

In the production method according to the present invention, the polymerization initiator includes an azo initiator, a peroxide initiator, an oxidation-reduction initiator composed of a combination of redox compounds, and the like. It is preferable to use an oxidation-reduction initiator since the loss of the compound that generates radicals can be reduced. As another method, UV polymerization, a radiation polymerization method, etc. can also be utilized.

The amount of the polymerization initiator used varies depending on the molecular weight of the desired polymer, but may be used in an amount of 0.01 to 1.0 parts by weight based on 100 parts by weight of the organic solvent.

Non-limiting examples of water used in the step of dispersing the organic mixed solution in water to form a crude emulsion in the production method of the present invention is deionized water. The deionized water may be used in an amount of 100 to 800 parts by weight based on 100 parts by weight of the organic solvent.

In addition, the buffer for pH adjustment may be used a conventional buffer commonly used in the art, such as phosphate-based, carbonate-based, the amount may be used in 0.01 to 1 parts by weight based on 100 parts by weight of water or deionized water.

These ingredients are mixed with each other and then uniformly mixed with a mechanical mixer to form a crude emulsion, and then a minie is made using a homogenizer such as a microfludizer, Gaulin homogenizer, or ultrasonic homogenizer. Homogenization with a mullion can form a stable emulsion having a particle size of 50-1000 nm. However, when using a redox initiator, it is also possible to make the said mini-emulsion, put it in a reactor, and after the content reaches reaction temperature, one of the oxidizing agent and a reducing agent in the component may be added at once or continuously.

In the production method of the present invention, the step (b) is a step of adding at least one polymer forming monomer to the seed fine particles formed in the step (a) proceeds the polymerization process, the organic mixed solution and the polymer forming monomer The monomer is administered so that the weight ratio is 1:99 to 90:10. In this polymerization step, one or more monomers may be added in a temporary, split or continuous mode (including feeder feed formula) .If necessary, the monomers may be mixed with an emulsifier and water (deionized water) and prepared in an emulsion state. (including the feeder feed formula). The method of dosing is selected according to the conditions, but in order to suppress instability due to the increase of the particle surface area with the increase of the particle size as the seed grows due to the diffusion or polymerization of the monomers of the seed fine particles, additional emulsifiers and water It is possible to mix and administer (deionized water).

At this time, the emulsifier should be added to a concentration below the critical micelle concentration (CMC) to suppress the formation of new particles other than seed particles. However, the emulsifier used for administration with the monomer in the polymerization reaction step may be the same as or different from the emulsifier used when preparing the liquid fine particle miniemulsion of the miniemulsion forming step.

In addition, when the monomer is mixed with water (deionized water) and an emulsifier and added to the emulsion state, there is an advantage that can help to diffuse into the seed fine particles by increasing the surface area of the monomer to be added later. In addition, the polymerization initiator may be further added temporarily, separately or continuously during the polymerization reaction, and the initiator may be added together with one or more monomers or separately. The initiator that can be used in the above step may use one or more selected from the group consisting of peroxides, azo compounds and mixtures of these and compound (s) causing their redox reaction, independently of the initiator of the minimization formation step. have. In the process of the present invention, the initiator must be added in at least one step of the miniemulsion production step or the polymerization reaction step.

The polymerization reaction temperature and conditions in the polymerization step are the same as in the general emulsion polymerization method or the miniemulsion polymerization method, and the internal reaction temperature is added to the reactor in the reactor, and the monomer is injected (continuous and divided doses) and stirred at a desired rate. While the half-life of the compound that thermally decomposes to generate gas and / or free radicals is 10 ° C. or less, preferably 15 ° C. or less, and more preferably 20 ° C. or less, than the decomposition temperature at 10 hours. The polymerization can be advanced. If the hydrogen ion concentration of the water is changed during the polymerization reaction, the stability of the particles may be broken, and a buffer may be further added to prevent such a phenomenon.

After the polymerization is completed, it is preferable to remove the organic solvent contained in the composite nanoparticle emulsion (latex). The organic solvent is used to induce the solubility of a compound that thermally decomposes before polymerization to generate gas and / or free radicals and to induce the desired morphology of the composite nanoparticles during the polymerization process. It is desirable to eliminate it because it can cause problems in the utilization phase. Examples of the removal method may include, but are not limited to, steam stripping and vacuum distillation, and may use process techniques well known in the art.

After the organic solvent is removed, an emulsion (latex) may be used as it is, depending on the application, and may be used as a powder by removing water.

The composite nanoparticles prepared according to the present invention contain a compound that is thermally decomposed to generate gas and / or free radicals. When the temperature rises above a temperature at which the compound can be thermally decomposed, the compound is thermally decomposed. To generate gas and / or free radicals. The composite nanoparticles of the present invention may be expanded by the gas generated by the thermal decomposition, or the gas and / or free radicals generated by the thermal decomposition may be released outside the composite nanoparticle. At this time, examples of the gas generated by thermal decomposition include nitrogen, carbon dioxide, and the like. In addition, since the composite nanoparticles are nanoparticles having a size of 20 to 1000 nm, they are excellent in dispersibility when mixed with other materials.

Therefore, by using such a property, the composite nanoparticles of the present invention can be utilized as a combustion inhibitor, a blowing agent, a radical generating agent, an additive of an electrochemical device, a chemical reaction material, or various other uses.

The above-mentioned use is a non-limiting example of the utilization of the composite nanoparticles according to the present invention, and thus the present invention is suitable for various chemical reactions, various devices, structures, compositions, etc. It also includes using for various uses, such as a composition. In this case, the amount of the composite nanoparticles according to the present invention may be appropriately used depending on the intended use.

EXAMPLE

Hereinafter, the present invention will be described in detail with reference to the following Examples. However, the following examples are merely to illustrate the present invention and the present invention is not limited by the following examples.

(Example 1)

To 100 parts by weight of an organic solvent mixed with toluene and isooctane in a 2: 1 (weight ratio), a compound that thermally decomposes to generate gas and / or free radicals, VAm 110 (2,2 ') of Wako, Japan. 15 parts by weight of -Azobis (N-butyl-2-methylpropionamide) and 10 parts by weight of hexadecane were dissolved in a homogeneous solution using a mechanical stirrer, and then sodium lauryl sulfate was added to the solution. 0.5 parts by weight and 300 parts by weight of deionized water were added.

The mixed solution was mixed for 1 minute at 13000 rpm using Ika Lab.'S Ultra Turrax T50 to make a crude emulsion. The next step was to homogenize three times at 3,000 psi using the Microfluidics' Michaelrofluidizer 120E. The mullion was prepared.

In order to stabilize this miniemulsion, 0.5 parts by weight of sodium lauryl sulfate was further added to form a seed particulate miniemulsion.

This mini-emulsion was placed in a nitrogen-substituted polymerization reactor and 0.1 parts by weight of ethylenediaminetetraacetic acid (EDTA) and 0.01 parts by weight of ferrous sulfate, which were part of the oxidation-reduction initiator, in 150 parts by weight of deionized water compared to the central part of the mini-emulsion 100 And an aqueous solution in which 0.2 parts by weight of hydroxy methane sulfonic acid sodium dihydrate (Sodium Formaldehydesulfoxylate dihydrate or Rongalite) was dissolved was added.

And 92 parts by weight of styrene, a polymer forming monomer, 3 parts by weight of acrylonitrile, and 5 parts by weight of divinyl benzene, a crosslinking agent, cumene hydroperoxide as an oxidizing agent in an oxidation-reduction initiator. ) Was mixed with 0.5 parts by weight of the solution (28 parts by weight of the total solution compared to the mini-emulsion) while reacting by dividing through the pump for 2 hours while maintaining the reactor temperature at 60 ℃.

Then, the reaction was terminated after 12 hours while checking the conversion rate by additionally adding 0.5 parts by weight of cumin hydroperoxide, which is an oxidizing agent, in the redox initiator. The experimental results are shown in Table 1 below.

(Example 2)

20 parts by weight of Vazo-67 (2,2'-Azobis (2-methylbutanenitrile)) manufactured by DuPont, USA instead of VAm 110 of Wako, Japan as a compound that thermally decomposes to generate gas and / or free radicals. The same procedure as in Example 1 was carried out except that it was maintained as. The experimental results are shown in Table 1 below.

(Example 3)

99 parts by weight of vinylidene chloride and 5 parts by weight of vinylene monomer and 3 parts by weight of acrylonitrile and 5 parts by weight of crosslinking agent, butanediol dimethacrylate as a crosslinking agent. Except for the use of parts by weight and thermal decomposition to generate gas and / or free radicals, 20 parts by weight of Vazo-67 from DuPont, USA instead of VAm 110 from Wako, Japan, and the reaction temperature of 25 ° C. were maintained. It proceeded in the same manner as 1. The experimental results are shown in Table 1 below.

(Example 4)

Instead of 92 parts by weight of styrene as a polymer forming monomer, 3 parts by weight of acrylonitrile, and 5 parts by weight of divinylbenzene as a crosslinking agent, 89 parts by weight of vinylidene chloride, 9 parts by weight of acrylonitrile and 2 parts of butanediol dimethacrylate as a crosslinking agent Example 1 except that 20 parts by weight of Vazo-67 from Dupont, USA was used instead of VAm 110 from Wako, Japan, and thermally decomposed to generate gas and / or free radicals, and the reaction temperature was maintained at 25 ° C. Proceed in the same way as. The experimental results are shown in Table 1 below.

(Example 5)

Instead of 92 parts by weight of styrene as a polymer-forming monomer, 3 parts by weight of acrylonitrile and 5 parts by weight of divinylbenzene as a crosslinking agent, 75 parts by weight of styrene and 25 parts by weight of acrylonitrile were used, and thermally decomposed to provide gas and / or free radicals. As a compound to generate the reaction was carried out in the same manner as in Example 1 except that 20 parts by weight of Vazo-67 of DuPont, USA instead of VAm 110 of Wako, Japan, and the reaction temperature was maintained at 40 ℃. The experimental results are shown in Table 1 below.

(Example 6)

Instead of 92 parts by weight of styrene as a polymer forming monomer, 3 parts by weight of acrylonitrile and 5 parts by weight of divinylbenzene as a crosslinking agent, methyl methacrylate was used and thermally decomposed to generate gas and / or free radicals. The same procedure was followed as in Example 1 except that 20 parts by weight of Vazo-67 from DuPont, USA was used instead of VAm 110 from Wako, Japan, and the reaction temperature was maintained at 40 ° C. The experimental results are shown in Table 1 below.

Raw material name Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Seed blowing agent VAm110 (15) Vazo-67 (20) Vazo-67 (20) Vazo-67 (20) Vazo-67 (20) Vazo-67 (20) Organic solvent toluene / isooctane = 2/1 (100) Same as Example 1 Same as Example 1 Same as Example 1 Same as Example 1 Same as Example 1 Emulsifier Sodium Laurylsulfate (1) Same as Example 1 Same as Example 1 Same as Example 1 Same as Example 1 Same as Example 1 Jiangsu Handmade Hexadecane (10) Hexadecane (10) Hexadecane (10) Hexadecane (10) Hexadecane (10) Hexadecane (10) Deionized water (300) (300) (300) (300) (300) (300) Monomer Styrene (92) (92) - - (75) - Acrylonitrile (3) (3) - (9) (25) - Vinylidene chloride - - (99) (89) - - Methyl methacrylate - - - - - (100) Crosslinking agent Divinylbenzene (5) Divinylbenzene (5) Butanedioldimethacrylate (1) Butanedioldimethacrylate (1) - - Reaction temperature 60 ℃ 40 ℃ 25 ℃ 25 ℃ 40 ℃ 40 ℃ Particulate size 200 nm 400 nm 567 nm 150 nm 340 nm 160 nm  * The unit () represents parts by weight.

(Comparative Example 1)

20 parts by weight of Vazo-67 was dissolved in 120 parts by weight of methyl methacrylate immediately without seeding the liquid fine particles, and then mixed with 315 parts by weight of ion-exchanged water in which 0.5 parts by weight of sodium lauryl sulfate was dissolved. It was put in a resin kettle attached to the heated to 40 ℃ while replacing the air with nitrogen for 30 minutes. After the internal temperature reached 40 ° C., 0.5 part by weight of ammonium persulfate was added and the polymerization reaction proceeded for 2 hours.

After the polymerization was completed, the resin kettle was decomposed and examined, and as a result, about 20 parts by weight of polymer was agglomerated around the axis, and scale was formed on the wall. This phenomenon was caused by the fact that at the same time as the normal emulsion polymerization proceeded, some of the excess Vazo-67 dissolved in the monomer phase was decomposed and the polymerization by the free radicals (mass polymerization) proceeded simultaneously. There was no possibility. In addition, there was a problem that most of the remaining Vazo-67 remained in the lump part in the added Vazo-67 without participating in the polymerization.

Experiment 1 Measurement of Weight Change with Temperature of Composite Nanoparticles

In order to confirm the presence of a compound (VAm 110, or Vazo-67) that is pyrolyzed to generate gas and / or free radicals in the composite nanoparticles prepared in the example, the weight change with temperature is observed as follows. Thermogravimetric Analysis (TGA, Thermo-Gravimetric Analysis) was used.

That is, if a compound (VAm 110, or Vazo-67) that is pyrolyzed to generate gas and / or free radicals is thermally decomposed at a specific temperature, the weight loss of the produced composite nanoparticles is remarkable. It was proved that VAm 110 is present in the composite nanoparticles.

(Experiment 1-1)

Thermogravimetric Analysis (TGA) was performed on the composite nanoparticles prepared in Example 1. Analytical conditions were measured by changing the weight while changing the temperature from room temperature (23 ℃) to 200 ℃ at 10 ℃ / min, the results are shown in FIG.

In the analysis results of FIG. 1, the weight loss began to occur around 100 ° C., and there was about 15% weight loss (half life of VAm 110 to 110 ° C.) up to 200 ° C., thereby producing the composite nanoparticles prepared in Example 1 It was indirectly known that VAm 110 exists in the. In addition, it can be seen that the gas and / or free radicals generated by thermal decomposition are released to the outside of the composite nanoparticles prepared in Example 1.

(Experiment 1-2)

Thermogravimetric Analysis (TGA) was performed on the composite nanoparticles prepared in Example 2. Analytical conditions were measured for weight change while changing the temperature from room temperature (23 ° C.) to 300 ° C. at 10 ° C./min, and the results are shown in FIG. 2.

In the analysis results of FIG. 2, since the weight loss began to occur at about 70 ° C. and the rapid weight loss (half life of Vazo-67 was 67 ° C.) at 75 ° C., the composite nanoparticles prepared in Example 2 was Indirectly, Vazo-67 was present. In addition, the composite nanoparticles prepared in Examples 3 to 6 were subjected to thermogravimetric analysis (TGA) in the same manner as in Experiment 1-2 to obtain almost the same graphs.

Therefore, it was found that the composite nanoparticles prepared in Example 2 include a compound generating gas and / or free radicals, and the gas and / or free radicals generated by thermal decomposition are released to the outside of the composite nanoparticles.

According to the preparation method of the present invention, a liquid phase material in which a compound which is thermally decomposed to generate gas and / or free radicals is dissolved into a miniemulsion state and used as seed fine particles. Thus, the microemulsified liquid fine particles are used during the polymerization process. It can function stably as a seed to produce uniform and stable particles, minimizing the time and energy to produce seed particles.

Claims (18)

In the method for producing a composite nanoparticles that are thermally decomposed to generate gas and / or free radicals are dispersed in a polymer matrix or phase separated by forming a core in the polymer shell, (a) a compound that thermally decomposes to generate gas and / or free radicals; Hard water preparation; Preparing a seed particulate miniemulsion containing an emulsifier and an organic solvent; And (b) adding a monomer for forming a polymer to the seed fine particle miniemulsion, and emulsion-polymerizing the monomer using the seed fine particle miniemulsion as a seed. The method of claim 1, wherein the mini-emulsion of step (a), (Iii) a compound that thermally decomposes to generate gas and / or free radicals; Hard water preparation; And dissolving an emulsifier in an organic solvent to prepare an organic mixed solution. (Ii) dispersing the organic mixed solution in water to form a preemulsion; And (Iii) homogenizing the crude oil with a homogenizer to form a mini emulsion. The method of claim 1, wherein the mini-emulsion of step (a) further comprises one or more selected from the group consisting of an initiator for polymerization and a buffer for pH adjustment. The method of claim 1, wherein the polymer forming monomer of step (b) is added with at least one selected from the group consisting of an emulsifier, water and an initiator for polymerization. The process according to claim 1, further comprising (c) removing the organic solvent contained in the polymerization product after step (b). The method according to claim 1, wherein the polymerization in step (b) is performed at a temperature lower than a temperature at which the gas and / or free radical generating compound is decomposed. The method of claim 2, wherein the liquid constituents of the materials constituting the organic mixed solution have a solubility in water of 75 g / kg or less at 25 ° C. The method according to claim 1, wherein the compound that is thermally decomposed to generate gas and / or free radicals is at least one selected from the group consisting of azo compounds, organic peroxides, hydrazide compounds, and carbazide compounds. Way. The method of claim 1, wherein the organic solvent of the step (a) is characterized in that the boiling point 60 ~ 150 ℃ organic compound. The method of claim 1, wherein the polymer forming monomer is polymerized with free radicals in the miniemulsion seed; Water is insoluble or hydrophilic; And wherein the half-life of the compound which is thermally decomposed to generate gas and / or free radicals is polymerized at 20 ° C. or lower than the decomposition temperature when 10 hours. The method of claim 1, wherein the polymer forming monomer is a compound having an unsaturated double bond. The method of claim 11, wherein the compounds having an unsaturated double bond are (meth) acrylate compounds, (meth) acrylonitrile compounds, (meth) acrylic acid compounds, (meth) acrylamide compounds, styrene compounds, And a vinylidene chloride compound, a vinyl halide compound, and a butadiene compound. The method according to claim 1, wherein the hydrophobic agent has a solubility in water of 5 × 10 ⁻⁶ g / kg or less at 25 ° C., and has 12 to 20 hydrocarbons, 12 to 20 aliphatic alcohols, and 12 to 20 carbon atoms. A method of producing at least one member selected from the group consisting of acrylates composed of alkyl groups, alkyl mercaptans having 12 to 20 carbon atoms, organic substances, fluorinated alkanes, silicone oil compounds, natural oils and synthetic oils. The method of claim 1, wherein the emulsifier is at least one selected from the group consisting of anionic emulsifiers, cationic emulsifiers, nonionic emulsifiers, and reactive emulsifiers copolymerizable with monomers for polymer formation. The method of claim 2, wherein the weight ratio of the organic mixed solution and the polymer-forming monomer is 1:99 to 90:10. The composition ratio of the reactive component is 0.01 to 200 parts by weight of an organic solvent, and 5 to 200 parts by weight of a compound that is thermally decomposed to generate gas and / or free radicals based on 100 parts by weight of the polymer forming monomer. ; The manufacturing method characterized by the above-mentioned 100-10 weight part of organic solvents, 0.1-10 weight part of strong water agents, and 0.05-20 weight part of emulsifiers. A composite nanoparticle produced by the method of claim 1. The composite nanoparticles of claim 17, wherein the composite nanoparticles are bulk expanded by a gas generated by thermal decomposition or emit gas and / or free radicals generated by thermal decomposition to the outside.

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