KR100846720B1 - Monodisperse Color Polymer Particles and preparation Methods thereof - Google Patents

Abstract

Dispersing the monodispersed seed particles obtained by the dispersion polymerization to swell the seed dispersion obtained through the swelling step and adding the swollen polymer dispersion, the colorant, the crosslinking agent and the dispersion stabilizer, and polymerizing to prevent the leakage of the colorant , The monodisperse colored fine polymer particles having a monodispersed particle size distribution and having a cross-linking structure on the surface of the colored polymer fine particles by adding a primary or secondary swelling process and a colorant and a crosslinking agent, .

Monodisperse * Coloring * Polymer * Fine Particles

Description

TECHNICAL FIELD [0001] The present invention relates to monodisperse color polymer particles and preparation methods thereof,

Fig. 1 is a diagram illustrating a process for producing monodisperse colored polymer particles of the present invention.

The present invention relates to monodisperse colored polymer microparticles and a process for preparing the same, and more particularly, to a process for producing a swollen polymer dispersion by making a seed dispersion by re-dispersing monodispersed seed particles obtained by dispersion polymerization, To a process for producing monodisperse colored fine polymer particles having excellent solvent resistance and coloring property by forming a crosslinked structure in particles by absorbing and polymerizing a polymerizable monomer, a colorant and a crosslinking agent.

The crosslinked colored fine particles can be used in various fields such as various film coating agents, plastic coloring agents, fillers such as various inks (lnk), paints, and toners, and cosmetics.

In general, colored fine particles having a particle size of about 0.1 to 50 占 퐉 are widely used in many industrial fields, but their production is not easy. Methods for producing such colored fine particles include Suspension Polymerization, non-emulsifier polymerization, dispersion polymerization and Seed-Swelling Polymerization using semi-batch emulsion polymerization .

Conventional methods for producing colored particles include: a method of dyeing uncoloured polymer particles; a method of obtaining colored particles by suspension polymerization or emulsification of a monomer containing a colorant and then classifying the colored particles; a method of kneading a polymer and a colorant, A method of coating the surface of the polymer particles with a pigment, a method of mixing the polymer and the colorant with a strong shear stress, and penetrating the colorant into the resin particle to prepare a colored microcapsule.

Conventionally, as a method of dyeing uncoloured polymer particles, there is a problem in that the dye can not sufficiently permeate into the polymer particles, so that the dye is liable to be eluted and the color tone is thin.

Also disclosed is a technique of producing colored spherical fine particles by suspension polymerization in Korean Patent Publication No. 1992-0003120 by a method of obtaining colored particles by suspension polymerization or emulsification of a monomer containing a colorant and then classifying the colored particles. However, in the suspension polymerization, the polymer particles are produced by dispersing monomers existing in the aqueous phase by mechanical force, and thus the prepared polymer particles have a particle size of at least 탆 or more, and particles are dispersed by mechanical force Coarse particles tend to be generated and the particle size distribution tends to be wide.

Therefore, there is a problem in that a separate device is required to control the particle size and the particle distribution. Further, when the affinity between the colorant and the monomer is low, the polymerization reaction may be inhibited by the coloring agent.

The method of kneading a polymer and a colorant, and then preparing and classifying the particles is a method of melting and kneading various raw materials, and then pulverizing the mixture to form fine particles. The final particles are not spherical but have a particle size distribution. There is a problem that complicated processes are followed.

In the method of coating the surface of the polymer particles with a pigment, there is a problem that the pigment tends to fall off because the pigment is physically attached to the surface of the particle.

A method of mixing a resin and a colorant with a strong shear stress and penetrating a colorant into resin particles to produce a colored microcapsule comprises mixing a styrene acrylic acid resin and a colorant dissolved in a solvent or water with a strong shear stress, A method for producing microcapsules is disclosed in Japanese Patent Application Laid-Open No. 8-269207. However, there is a problem that the particle size distribution of the colored particles is wide.

Therefore, the present inventors have conducted studies to solve the problem that it is difficult to obtain a monodisperse particle size distribution although particles of nano or micron size can be obtained by using suspension polymerization and emulsion polymerization, which are methods for producing fine colored polymeric particles in the past Dispersing the monodisperse seed particles obtained by dispersion in a dispersion, swelling the seed dispersion through a swelling step, and then adding a reactive monomer, a colorant, a crosslinking agent and a dispersion stabilizer, and polymerizing to prevent leakage of the colorant. The result is that the polymer colored fine particles having a monodisperse particle size distribution can be produced, and the monodispersed colored polymer fine particles thus prepared have excellent solvent resistance and coloring properties, and thus the present invention has been accomplished.

Accordingly, an object of the present invention is to provide monodisperse colored polymer fine particles having a monodisperse particle size distribution and excellent solvent resistance and coloring properties.

Another object of the present invention is to provide a method for producing the monodisperse colored polymer fine particles.

The monodisperse colored fine polymer particles for achieving the present invention as described above can be prepared by dispersing monodisperse seed particles obtained by dispersion polymerization to form a seed dispersion and then forming a swollen polymer dispersion through a swelling step and adding a colorant, Absorbing and polymerizing the dispersion stabilizer, and has an average particle size of 1 to 100 μm and a relative standard deviation of the particles of 10% or less.

Hereinafter, the present invention will be described in detail.

Disclosed is a method for producing monodisperse colored fine polymer particles by dispersing polymerization. Specifically, the present invention relates to a method for producing monodispersed colored fine polymer particles by swelling a seed dispersion, introducing a multifunctional crosslinking agent, a colorant and a dispersion stabilizer thereto, Monodisperse colored polymer fine particles and a method for producing the same.

The crosslinked colored fine polymer microparticles of the present invention are obtained by firstly dissolving the primary polymerization initiator and the dispersion stabilizer in an organic solvent, followed by dispersion polymerization to prepare seed particles, and a step of dissolving the seed particles prepared in the first step in an emulsifier A second step of swelling the swollen polymer dispersion, a colorant and a cross-linking agent in a second step of introducing a secondary polymerizable monomer in which an oil-soluble initiator is dissolved into a seed dispersion, Stabilizing with a dispersion stabilizer, raising the temperature to an internal temperature of 50 to 90 ° C, and finally polymerizing to obtain crosslinked colored polymer particles having a particle size of 1 μm to 100 μm.

In the first step, seed particles are prepared by dissolving an oil-soluble initiator and a dispersion stabilizer in a polymerizable monomer to prepare monodispersed seed particles.

Examples of the polymerizable monomer to be used herein include aromatic vinyl monomers, acrylic acid or methacrylic acid having 1 to 20 carbon atoms, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (Meth) acrylate monomers having 1 to 4 carbon atoms such as methyl (meth) acrylate, butyl (meth) acrylate and isobutyl (meth) acrylate. Although the amount of the reactive monomer to be used is not particularly limited, it is preferably 100 wt% or less, more preferably 1.0 to 80 wt%, of the total composition included in the first step.

The oil-soluble initiator may be any conventionally known one, and in the present invention, particularly, 2,2'-azobis (2-methylpropionitrile), 2,2'-azobis (2-methylbutyl Nitrile), 2,2'-azobis (2-isobutyronitrile), 2,2'-azobis (2-cyclopropylpropionitrile), 1,1'-azobis (cyclohexane 1-carbonitrile ), And dimethyl-2,2'-azobis (2-methylpropionate). The content thereof is suitably 0.01 to 1 part by weight relative to the weight of the reactive monomer.

In addition, the dispersion stabilizer of the present invention can be used as a dispersion stabilizer in the present invention such as polyvinylpyrrolidone, polyvinyl alcohol, methylcellulose, ethylcellulose, sodium carboxymethylcellulose, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, sodium polymethacrylate, gelatin , Polyacrylamide, and polyethylene oxide, and the content thereof is preferably 0.2 to 20.0 parts by weight based on the weight of the polymerizable monomer.

The organic solvent used in the dispersion medium of the present invention may be selected from the group consisting of aliphatic alcohols such as methanol, ethanol, 1-propanol, 2-propanol and isopropanol, acetonitrile, acetone acetone, dimethyl ketone, and methyl ethyl ketone. These solvents may be used alone or in combination of two or more.

In the second step, the seed particles are re-dispersed in the emulsion-dissolved water phase to prepare a seed dispersion.

The emulsifier (or surfactant) used in the present invention can be selected from conventional conventionally used anionic surfactants, cationic surfactants, and nonionic surfactants. Specific examples thereof include alkylbenzene sulfonate salts such as dodecylbenzene sulfonate, undecylbenzene sulfonate, tridecylbenzene sulfonate, and nonylbenzene sulfonate; alkylsulfuric acid salts such as sodium dodecyl sulfate ester and dodecyl sulfate ester ammonium; Anionic surfactants such as ester salts; Cationic surfactants such as cetyltrimethylammonium propamide, hexadecylpyridinium chloride and hexadecyltrimethylammonium chloride; And non-ionic surfactants such as polyoxyethylene aryl glycidyl nonylphenyl ether sulfate such as lypyridinium.

Also, polyethylene glycol alkyl ethers such as polyethylene glycol nonylphenyl ether; Reactive emulsifiers having reactive groups such as vinyl group, acrylonyl group and aryl group; Water-soluble polymer compounds such as polyvinyl alcohol and polyacrylate salts can be selected and used for producing a seed dispersion. The content of the emulsifier is 0.05 to 8 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the seed particles.

The seed particles prepared in the first step are added to the aqueous phase in which the emulsifier is dissolved and re-dispersed to prepare a seed dispersion.

In the next step, a secondary polymerizable monomer in which an oil-soluble initiator is dissolved is added to the seed dispersion prepared in the second step and swelled.

The secondary polymerizable monomer used here is the same as the polymerizable monomer used in the first step, and the oil-soluble initiator is usually preferably 0.3 to 1.0 part by weight based on the weight of the secondary polymerizable monomer. In this case, the added oil-soluble initiator is added only for the reaction of the fourth step, and in principle, the reaction does not occur in the third step.

The swelling process of the third step is carried out by adding a secondary polymerizable monomer having the above-described oil-soluble initiator dissolved therein to the prepared seed dispersion, raising the temperature to 30 to 40 占 폚, and vigorously stirring for 12 to 24 hours.

Then, a colorant and a crosslinking agent are added to the swollen polymer dispersion and polymerized to produce final monodispersed colored fine particles.

Specific examples of the coloring agent used for obtaining the colored fine particles include dyes and pigments. Specific examples thereof include Rhodamine B, Rhodamine 6GCP (Sumitomo Chemical), Methyl violet FN, Victoria Blue FN and the like Of an alkaline dye; Water-soluble dyes such as quinoline yellow SS-5G, quinoline yellow GC (central synthetic chemicals), acid magenta O, methyl violet FB, and Victoria blue FB .

Examples of useful dyes include anthraquinone-based and azine-based dyes such as 1,4-diamino-2,3-diphenoxyanthraquione, And Xanthene series. Specific examples thereof include Oil orange B, Oil blue BA, Azo sole brilliant yellow, and the like. ) 4GF, Azo sole first blue GLA, and oil red TR-71. Examples of the organic pigments include inorganic pigments such as carbon black, titanium black, titanium white, zinc yellow and red iron oxide, and organic pigments such as monoazo pigments, azo pigments such as disazo pigments, phthalocyanine and quinacridone. These coloring agents may be used alone or in combination of two or more.

The amount of the colorant to be used is not particularly limited, but is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 7 parts by weight, based on 100 parts by weight of the swollen polymer dispersion. When the amount is less than 0.05 part by weight, scattering of the crosslinked colored fine particles may occur. When the amount is more than 10 parts by weight, there is a problem that aggregation or polymerization stability is lowered and the yield is lowered.

In the present invention, by introducing a cross-linking agent into the swollen seed dispersion particles to form a cross-linked structure, colored polymer fine particles having excellent solvent resistance and coloring property can be obtained. Such a crosslinking agent is added in order to prevent the coloring agent from escaping from the polymer fine particles, and the added crosslinking agent serves as a coating film forming a crosslinking structure on the surface of the coloring agent. As the crosslinking agent used to form such a crosslinking structure, a multifunctional monomer having a bifunctional or higher functionality may be selected and used. As the polyfunctional mono, for example, 1,2-ethanediol diacrylate, 1,3-propanediol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, Diol diacrylate, 1,6-hexanediol diacrylate, divinylbenzene, ethylene glycol diacrylate, propylene glycol diacrylate, butylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate , Polypropylene glycol diacrylate, polybutylene glycol diacrylate, allyl acrylate, 1,2-ethanediol dimethacrylate, 1,3-propanediol dimethacrylate, 1,3-butanediol dimethacrylate Butanediol dimethacrylate, 1,5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, butylene Gly One selected from the group consisting of ethylene glycol dimethacrylate, dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate, allyl methacrylate and diallyl maleate And the content thereof is usually 0.5 to 50 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of the swollen polymer dispersion.

The dispersion stabilizer included in the fourth step may be selected from the group consisting of polyvinylpyrrolidone, polyvinyl alcohol, methylcellulose, ethylcellulose, sodium carboxylmethylcellulose, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, sodium polymethacrylate Gelatin, polyacrylamide, and polyethylene oxide.

The particle diameter of the colored polymer microparticles of the present invention can be controlled according to the composition of the reaction, the reaction temperature, the stirring conditions and the like, but a method of mixing and stirring with strong shear stress can be selected for polymerization stability.

The colored polymer fine particles prepared as described above are washed and dried by a conventional method to prepare monodisperse colored polymer fine particles according to the present invention.

The average particle size of the monodisperse colored polymer fine particles prepared according to the present invention is 1 to 100 탆, and the relative standard deviation of the particles is 10% or less.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples. The following examples are provided to facilitate understanding of the present invention. However, the present invention is not limited to these examples. no.

Example 1

Step 1: Preparation of monodispersed seed particles

After 1.2 g of 2,2'-azobis (2-isobutyronitrile) was dissolved in 80 g of methyl methacrylate in a 2 L round-bottomed flask, the internal temperature reached 50-70 ° C., and 560 g of ethanol and 560 g of dispersion stabilizer polyvinylpyrrolidone (PVP) were added. Nitrogen was purged for 5 minutes and then polymerized at 250 rpm for 12 to 24 hours under stirring to prepare monodispersed seed particles.

Polymerization conversion was 99.3% in this polymerization, and monodispersed seed particles having an average particle size (d50) of the obtained seed particles and a standard deviation (C.v) of particle size of 4.2% were obtained.

Step 2: Preparation of seed dispersion

To 960 g of ion-exchanged water, 9.6 g of sodium lauryldodecyl sulfate ester as an emulsifier was dissolved, 240 g of the monodispersed seed particles prepared in the first step was added to a 2 L reactor and re-dispersed in a nitrogen stream to prepare a seed dispersion Respectively.

Step 3: Preparation of a swollen polymer dispersion

A solution obtained by dissolving 0.6 g of 2,2'-azobis (2-isobutyronitrile) as an oil-soluble initiator in 100 g of methyl methacrylate was added to 1200 g of the seed dispersion prepared in the second step, After stirring vigorously for 1 hour, the internal temperature was raised to 30 to 40 DEG C and polymerization was carried out for 12 to 24 hours to prepare a swollen polymer dispersion.

In this polymerization, the polymerization conversion was 98.7%, and the monodisperse swollen polymer dispersion particles having an average particle size (d50) of the obtained particles of 10.3 mu m and a standard deviation (C.v) of particle size of 5.1% were obtained.

Step 4: Preparation of colored fine particles

6.7 g of oil blue BA as a coloring agent, 168 g of ethylene glycol diacrylate as a crosslinking agent, and 8.4 g of polyvinylpyridone as a dispersion stabilizer were added and dissolved in 672 g of the swollen polymer dispersion, and then the internal temperature was raised to 50 to 90 캜 To prepare crosslinked colored polymer particles by polymerization. The colored particles were washed with distilled water five times, washed with isopropyl alcohol, dried in a vacuum drier to a moisture content of less than 0.5%, and classified with a dry type classifier to finally produce monodispersed colored fine polymer particles.

The polymerization conversion of the polymer finally prepared was 95.8%, and the monodisperse colored crosslinked colored fine particles having an average particle size (d50) of 10.5 탆 and a standard deviation (C.v) of particle size of 7.4% were obtained.

Example 2

Monodispersed colored polymer fine particles were prepared in the same manner as in Example 1 except that dimethyl 2,2'-azobis (2-isobutyronitrile) was used instead of the oil-soluble initiator 2,2'-azobis Methyl propionate) was used to prepare monodispersed colored polymer microparticles.

Comparative Example 1

Monodispersed colored fine polymer particles were prepared in the same manner as in Example 1 except that the colored fine particles were prepared without using a crosslinking agent in the fourth step.

Comparative Example 2

Monodispersed colored fine polymer particles were prepared in the same manner as in Comparative Example 1 except that benzoyl peroxide was used instead of the oil-soluble initiator 2,2'-azobis (2-isobutyronitrile) to prepare colored fine particles Respectively.

In each of Comparative Examples and Examples, the yield of the polymerized liquid after polymerization and the polymer were washed, separated and dried through a 150 mesh standard netting, and the average particle size and particle size distribution were measured with a particle size analyzer. The color change by the elution test was carried out by adding the colored polymer fine particles to 15 ml of ethanol and stirring at room temperature for 30 minutes and then eluting the dye in the colored fine particles at 600 nm with a UV-vis (Shimadzu model UV-2101 PC) ), And the color change was visually confirmed. Also, the solvent resistance of the particles was confirmed by measuring the cross-link density of the particles. In the test method, particles were added to toluene and reacted for 12 hours on an ultrasonic stirrer to reach an equilibrium state to extract the solvent. The crosslinked particles were centrifuged at 4 ° C, 12,000 rpm, for 1 hour to separate the gel phase and the solution phase. The separated gel phase was dried for 24 hours, and the crosslinking density was calculated by the following equation.

- Crosslink density (%) = weight of dried gel (Wd) / initial weight of particles used (Wi) * 100

Yield (%) Average particle diameter (占 퐉) Particle size standard deviation (%) Colorability change Solvent resistance (crosslink density,%) Example 1 95.8 10.5 7.4 No change  53.0 Example 2 95.2 10.8 8.1 No change 51.5 Comparative Example 1 84.4 9.8 12.5 Slightly discolored 6.4 Comparative Example 2 85.5 10.5 34.7 Fading 4.8

As can be seen from the results of Table 1, in the case of the colored polymer particles produced according to the present invention, there is no color change due to the elution of dye from the colored polymer, and the solvent resistance is excellent.

As described in detail above, the colored polymer fine particles prepared according to the present invention have a monodisperse particle size distribution, and by forming a crosslinked structure on the surface of the colored fine polymer particles by adding a primary or secondary swelling process, a colorant and a crosslinking agent It is excellent in solvent resistance and colorability.

Claims (5)

delete A first step of dissolving a polymerizable monomer, an oil-soluble initiator, and a dispersion stabilizer in an organic solvent, followed by dispersion polymerization to prepare monodispersed seed particles; A second step of preparing a monodispersed seed dispersion by redispersing the monodispersed seed particles in an aqueous phase in which an emulsifier is dissolved; A third step of introducing and swelling a polymerizable monomer having an oil-soluble initiator dissolved in the monodispersed seed dispersion; And And a fourth step of adding a colorant, a crosslinking agent, and a dispersion stabilizer, and polymerizing the resultant to prevent leakage of the colorant. 3. The composition of claim 2, wherein the colorant is selected from the group consisting of an aqueous dye selected from an alkaline dye and an acidic dye; Oil soluble dyes; Inorganic pigments; And organic pigments. The method for producing fine particles of monodisperse colored polymer particles according to claim 1, wherein the polymer particles are contained in an amount of 0.05 to 10 parts by weight based on 100 parts by weight of the swollen polymer dispersion. 4. The method for producing monodisperse colored fine polymer particles according to claim 3, wherein the oil-soluble dye is at least one selected from anthraquinone-based, azine-based, and xanthan-based solvent-soluble dyes. 3. The composition of claim 2, wherein the crosslinking agent is selected from the group consisting of 1,2-ethanediol diacrylate, 1,3-propanediol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, Diethylene glycol diacrylate, butylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, diethylene glycol diacrylate, diethylene glycol diacrylate, diethylene glycol diacrylate, Acrylate, polypropylene glycol diacrylate, polybutylene glycol diacrylate, allyl acrylate, 1,2-ethanediol dimethacrylate, 1,3-propanediol dimethacrylate, 1,3-butanediol di Methacrylate, 1,4-butanediol dimethacrylate, 1,5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, Butylrangle One selected from the group consisting of styrene, styrene, styrene, styrene, styrene, acrylonitrile, styrene, styrene, styrene, styrene, Or more of the polyfunctional monomer is contained in an amount of 0.5 to 50 parts by weight based on 100 parts by weight of the swollen polymer dispersion.

Images