KR20190008804A - Polymer hollow particle, preparing method thereof, and composite comprising the polymer hollow particle - Google Patents

Abstract

A method for manufacturing polymeric hollow particles comprises: a first step of providing at least one expandable particle containing an expandable core and a thermoplastic polymer shell comprising a foaming agent in a substrate having an engraved pattern; a second step of removing excess expandable particles from the product in the first step; a third step of heat-treating the product in the second step to expand the expandable particles having the engraved pattern; and a fourth step of separating the polymeric hollow particles expanded according to the third step from the substrate. Disclosed are monodisperse polymeric hollow particles having low specific gravity and various shapes manufactured according to the manufacturing method and a composite comprising the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer hollow particle, a method for producing the hollow polymer particle, a composite material comprising the polymer hollow particle,

The present invention relates to polymer hollow particles, a method for producing the hollow polymer particles, and a composite comprising the polymer hollow particles, and more particularly, to a method for producing polymer hollow particles using expandable particles, and a polymer hollow particle prepared by the method .

Polymer particles have been widely used in various fields such as sustained release agents, optical materials, and chromatography media. Recent studies have been conducted on the use of polymeric particles as building blocks for the fabrication of complex structures. In such applications, the physical and chemical properties of polymer particles such as structure, size, shape, porosity, surface charge, hydrophilicity, and hydrophobicity affect the function of the particles, so they introduce complexity into the structure of the particles and uniformly Control is very important. The design of polymeric particles with various forms and physicochemical properties can further expand their applications.

Methods for producing polymer microparticles with controlled morphology and shape are known such as microfluidic systems, control of emulsion polymerization, and phase separation. However, in this manufacturing method, it is not easy to control the density characteristics of the particles, and the manufacturing process itself is complicated and needs to be improved.

One aspect of the present invention is to provide a method for producing polymer hollow particles having various shapes by using heat expandable particles.

Another aspect of the present invention is to provide a polymer hollow particle having a low specific gravity, which is produced by the above-described production method and has a simple dispersibility.

Another aspect is to provide a composite containing the above-mentioned polymeric hollow particles.

According to one aspect,

A first step of providing at least one expandable particle comprising an expandable core comprising a blowing agent and a thermoplastic polymer shell to a substrate having a decoratched pattern;

A second step of removing excess expandable particles from the result of the first step;

A third step of heat-treating the resultant product of the second step to swell the intumescent patterned expandable particles; And

And a fourth step of separating the expanded polymeric hollow particles from the substrate according to the third step.

A line or a hole pattern may be formed on the substrate having the engraved pattern to form a line or hole pattern on at least one surface of the polymer hollow particles.

According to other aspects

The polymer particles are monodispersed particles prepared according to the above-described production method and comprising an expandable core and a thermoplastic polymer shell, and have a specific gravity of 0.001 to 1 g / cm ³ .

According to another aspect polymer hollow particles; And a composite comprising at least one material selected from the group consisting of an electron conductive material, a material having electromagnetic wave shielding performance, a thermoelectrically conductive material, and a polymer resin.

The composite may comprise polymeric hollow particles; And a coating film disposed on the surface of the polymer hollow particles and containing a coating film containing at least one substance selected from the group consisting of an electron conductive material, a material having electromagnetic wave shielding ability, a thermoelectrically conductive material and a polymer resin, Particles and at least one material selected from an electron conductive material, a material having an electromagnetic wave shielding performance, a thermoelectrically conductive material, and a polymer resin.

According to one aspect, polymer hollow particles having various shapes can be produced by using heat expandable particles. When such expandable particles are supplied and heated in a pattern of various shapes, the polymer particles expand to fit the shape of the pattern and the shape thereof is controlled, so that the shape is easily controlled and the specific gravity is low.

FIG. 1A is a view for explaining a manufacturing process of monodispersed polymeric hollow particles according to one embodiment.
FIG. 1B is a view for explaining the characteristics of the polymer hollow particles according to one embodiment.
1C-1F are optical microscope photographs of polymer hollow particles according to one embodiment.
FIGS. 2A to 2C are optical microscope photographs of polymer hollow particles prepared according to Example 1, Examples 5 and 6. FIG.
3A to 3G are optical microscope photographs of polymer hollow particles prepared according to Examples 8 to 14.
FIG. 3H is an enlarged view of the square area of FIG. 3G.
FIG. 4A is an optical microscope photograph of the polymer hollow particles produced according to Example 14. FIG.
4B is an enlarged view of the square area of FIG. 4A.

Hereinafter, polymer hollow particles according to one embodiment, a method for producing the same, and a composite containing the polymer hollow particles will be described in more detail.

A first step of providing at least one expandable particle comprising an expandable core comprising a blowing agent and a thermoplastic polymer shell to a substrate having a decoratched pattern;

A second step of removing excess expandable particles from the result of the first step;

A third step of heat-treating the resultant product of the second step to swell the intumescent patterned expandable particles; And

And a fourth step of separating the expanded polymeric hollow particles from the substrate according to the third step.

By using the above-mentioned production method, it is possible to easily produce monodispersed polymer hollow particles of various shapes and low specific gravity by using expandable particles having the characteristic of expanding by heat.

The expandable particles provided in the pattern engraved in the first step may have at least one, for example from 1 to 1000, for example from 1 to 500, for example from 1 to 500, of monodisperse or polydisperse type It is possible to control the density and the shape of the polymer particles which have been expanded in the monodisperse type and are provided in the range of 100. Even if the expandable particles, which are the starting materials, are not monodisperse but polylactic, the monodispersed polymer hollow particles can be produced as the final object. These polymer hollow particles are uniform in size and substantially do not aggregate with each other.

When the diameter distribution of the polymer hollow particles is measured by dynamic light scattering, the diameter of the particles is well controlled so that the degree of dispersion of the particle size is 5% or less, for example, 1% or less, for example, 0.1% Is 0.01% or less, for example, 0.0001 to 0.01%.

Wherein the first step comprises mixing one or more expandable particles comprising the expandable core and the thermoplastic polymer shell with a solvent to provide a substrate having a wet intaglio pattern or providing one or more expandable particles comprising an expandable core and a thermoplastic polymer shell Can be provided as a dry type. Here, the dry type means a rubbing method, a spray method and the like.

In the above step 3, the heat treatment is performed at a temperature of 50 to 170 ° C, for example, 90 to 120 ° C, for example, 100 to 120 ° C. The heating rate during the heat treatment is 0.1 to 20 占 폚 / min, for example, 10 占 폚 / min. When the heat treatment temperature and the temperature raising rate are within the above ranges, the expandable particles are smoothly expanded, and the expanded polymer hollow particles having the desired polymer shell thickness can be obtained. Especially, when the rate of temperature rise is within the above-mentioned range, structural defects of the core and the shell or intumescent particles without breakage can be maintained. As a result, it is possible to prevent the true specific gravity of the polymer hollow particles from being larger than expected, or the expansion magnification can not be controlled as desired so that the thermal expansion property can be prevented from deteriorating. The substrate having the intaglio pattern is, for example, a substrate having microwells.

If the expandable particles are provided in the microwell of the mold in the form of an expandable particle water dispersion, unnecessary solvents can be removed in the heat treatment process described above. And the expansion progresses in the heat treatment process, and the heat treatment time can be changed in the range of, for example, 1 second to 24 hours.

The substrate on which the pattern is intaglio patterned can be manufactured using the photolithography process and polydimethylsiloxane (PDMS), a thermosetting silicone polymer.

After a photosensitive resin is coated on a silicon substrate, ultraviolet rays are selectively irradiated through a photomask having a pattern of various circular, triangular, square, pentagonal, hexagonal, etc. having a predetermined width and depth, And removed through a developer to obtain a mold having a desired pattern.

PDMS, which is a thermosetting polymer, was applied to the mold thus obtained and cured at a temperature of 60 to 90 DEG C for 10 to 30 hours to separate the substrate from the silicon substrate. Then, it was exposed in an oxygen atmosphere to induce formation of a hydrophilic chemical group on the surface A PDMS substrate having intaglio pattern of polygonal shape was obtained. The channel member is manufactured by thermally curing the PDMS applied in the above.

The PDMS channel member obtained in the flat state is bonded to the PDMS substrate having the various types of intaglio patterns obtained from the above, and integrated to manufacture the device.

The size of the engraved pattern is not particularly limited, and depends on the size of the desired polymer hollow particles. It is possible to control the shape of the expanded polymer hollow particles by controlling the shape of the intaglio pattern in the thickness direction.

For example, if the length of one side on a plane is defined as A, the number of sides is defined as N, and N is varied in the range of 1 to 100, the intensely patterned pattern can be obtained by changing the shape of the expanding particles The shape of the expandable particles can be variously changed in an isotropic shape.

The length of one side on the plane of the intaglio pattern is defined as A, the number of sides is defined as N, and N is varied in the range of 1 to 100, whereby the shape of the expanding particle An expanding particle that deforms into an anisotropic shape can be used.

The width and height of the engraved pattern are not limited to a particular shape, for example, the width of the engraved pattern is 10 nm to 1,000 μm and the height is 10 nm to 1,000 μm.

It may be aged for 1 to 100 minutes in the middle of the above-mentioned heat treatment. Through this process, the expansion ratio of the expandable particles can be maximized and unnecessary air can be removed.

The shape of the mold in the method of manufacturing the polymer hollow particles according to one embodiment can be variously formed according to the shape of the desired polymer hollow particles such as a circle, a square, and a rectangle.

The polymer hollow particles according to one embodiment are easy to control their shape as desired as shown in FIG. 1B (see complexity # 1 and FIG. 1C). The polymer hollow particles of the present invention can control the heat treatment temperature or the like to round the edge or control the sharpness (see complexity # 2 and FIG. 1d). As shown in FIG. 1C, the polymer hollow particles can control the number of particles such as 1, 2, and 3 particles as desired (see complexity # 3 and FIG. 1e). May have one-body particles, primary particles, or secondary particle forms. Secondary particles are aggregates of primary particles. When the polymer hollow particles are integral particles, there is almost no grain boundary in the particles.

The polymer hollow particles according to one embodiment can be surface-treated to prevent aggregation and adhesion of the particles. The surface treatment is, for example, coating of a fluorine-based material. As the fluorine-based material, a low-molecular substance such as 1,1-difluoroethane is used.

The polymer particles of the present invention can form patterns of holes, lines and the like on their outer surfaces (upper, lower and side surfaces) as desired (see complexity # 4 and Figure 1F).

The content of core in the expandable particles is from 2 to 85% by weight, for example from 0.1 to 5.0% by weight, for example from 1 to 3% by weight, based on the total weight of the expandable particles, and the thermoplastic polymer shell comprises 95% To 99.9% by weight. The thickness of the thermoplastic polymer shell is 0.1 to 10 탆.

The average particle diameter of the expandable particles is, for example, 0.2 to 50 占 퐉.

In the expandable particles, the blowing agent is heated at a temperature higher than the softening point temperature of the thermoplastic resin constituting the polymer shell to expand the expandable particles such that the volume expansion ratio thereof is about 10 times or more, for example, 0.01 to 10 times.

The polymer hollow particles according to one embodiment have large pores inside due to expansion, and can be used as a filler in a polymer substrate to be applied as a structure requiring a low specific gravity. When the polymer hollow particles of the present invention are used as a filler, various properties such as density, transparency, refractive index, sound insulation and insulation of the product can be easily adjusted as desired.

The thermoplastic resin is a polymer obtained from a polymer obtained from a polymerizable monomer or a reaction product of a polymerizable monomer and a crosslinking agent, and the polymerizable monomer includes a nitrile monomer, a carboxylic acid monomer, a (meth) acrylic acid ester monomer, an acrylamide monomer , Maleimide monomer, vinyl ether monomer, styrene monomer, vinyl ketone monomer, aromatic divinyl monomer, N-vinyl monomer, halogenated vinyl monomer, and combinations thereof.

Examples of the nitrile-based monomer include acrylonitrile, methacrylonitrile, a-chloracrylonitrile, a-ethoxyacrylonitrile, and fumaronitrile. And carboxylic acid monomers include, for example, carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and citraconic acid; Vinylidene chloride, vinyl acetate; (Meth) acrylate, isobutyl (meth) acrylate, isobonyl (meth) acrylate, cyclohexyl (meth) acrylate, (Meth) acrylate, benzyl (meth) acrylate, carboxyethylene acrylate, and the like. Examples of the styrene-based monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p- Dodecylstyrene, pn-dodecylstyrene, n-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, Examples of the acrylamide-based monomer include acrylamide, substituted acrylamide, methacrylamide, substituted methacrylamide, and the like. Examples of the maleimide-based monomer include N-phenylmaleimide, N- (2-chlorophenyl) maleimide, N-cyclohexylmaleimide and N-laurylmaleimide.

Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether. Vinyl ketone monomers include vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone.

Examples of the aromatic divinyl-based monomer include divinylbenzene, divinylnaphthalene, and the like.

The (meth) acrylic acid ester monomer may be, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) Acrylate, propyl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl Acrylate, phenyl (meth) acrylate, isobonyl (meth) acrylate

(Meth) acrylate, benzyl (meth) acrylate,? -Carboxyethyl acrylate, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl .

Examples of the N-vinyl monomer include N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone and the like. Examples of the vinylidene halide monomer include vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, etc. The crosslinking agent includes allyl methacrylate, triacryl acrylate, triallyl isocyanate, ethylene glycol di (meth) Acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,9- Acrylate, trimethylolpropane trimethacrylate, glycerol dimethacrylate, dimethylol-tricyclodecane (meth) acrylate, ethylene glycol di (meth) acrylate, neopentyl glycol di Diacrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, neopentyl glycol acrylate esters Acrylic acid esters such as 2-hydroxy-3-acryloyloxypropyl methacrylate, hydroxypivalic acid neopentylglycoldiacrylate, ditrimethylolpropane tetraacrylate, 2-butyl- 2-ethyl-1,3-propanediol diacrylate, and combinations thereof. The weight average molecular weight of the polyethylene glycol in the polyethylene glycol di (meth) acrylate may be 200, 400 or 600.

The blowing agent constituting the core of the expandable particles includes a non-fluorinated hydrocarbon compound having a low boiling point which becomes a gaseous phase at a temperature below the softening point of the thermoplastic resin of the thermoplastic resin polymer shell.

The foaming agent maintains an initial decomposition temperature of, for example, 150 ° C or higher and a maximum foaming degree at 210 ° C to 240 ° C. The core of the expandable particles has a thermal expansion starting temperature of -20 to 150 캜, for example, -15 to 100 캜, for example, -12 to 50 캜 and a maximum thermal expansion temperature of 160 to 170 캜.

The content of the expandable core is 5 to 30% by weight based on the total weight of the expandable particles. The foaming agent may be selected from, for example, propane, propylene, butene, n-butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, octane, petroleum ether, Lt; / RTI > amide.

The thermoplastic resin constituting the polymer shell may contain, for example, a (meth) acrylic first recurring unit as an essential constituent, and a second recurring unit of a nitrile, a second recurring unit of the (meth) And a third repeating unit having no reactivity.

The thermoplastic resin may contain the first repeating unit and the second repeating unit at an arbitrary mixing ratio.

According to one embodiment, the content of the first (meth) acrylic repeating unit is 10 to 50% by weight, for example, 15 to 30% by weight based on the total amount of the repeating units, 30 to 80% by weight, for example 35 to 50% by weight, based on the total content of the repeating units.

The third repeating unit may be at least one selected from the group consisting of polyvinyl chloride, N-methylol (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate.

The thermoplastic resin may contain the first repeating unit, the second repeating unit and the third repeating unit in an arbitrary mixing ratio.

The content of the third repeating unit is 10 to 50% by weight, for example, 35 to 45% by weight.

The thermoplastic resin includes, for example, vinyl chloride-co-acrylonitrile-co-methyl methacrylate copolymer. The content of the acrylonitrile repeating unit is 10 to 50% by weight, the content of the repeating unit of methyl methacrylate is 30 to 80% by weight, and the content of the vinyl chloride repeating unit is 10 to 50% by weight.

When the expandable particles including the polymer shell containing the thermoplastic resin having the above composition are used, the expanded polymer hollow particles having the desired polymer shell thickness can be obtained, and after the expansion is completed, the structural defects of the core and the shell ) Or expandable particles without breakage, and has excellent specific gravity and thermal expansion properties of the polymer hollow particles.

Hereinafter, a method of producing the polymer hollow particles according to one embodiment will be described in more detail.

A microwell of a mold that is a substrate with a patterned pattern provides one or more expandable particles comprising an expandable core comprising a blowing agent and a thermoplastic polymer shell. One or more of the expandable particles may be provided to the substrate by a dry method such as rubbing or spraying the microwell in powder form without any additional solvent.

Even though the expandable particles provided in the microwell are of the polydisperse type, the finally obtained polymer hollow particles have a monodisperse particle type with a very high degree of dispersion.

In the case of producing polymer hollow particles using a wet process, it is necessary to provide a mold lid, and it is necessary to dope the particles and to evaporate the solvent used in dispersing the particles in the microwells of the mold. In addition, the affinity and surface energy of the solvent for the mold using the wet process should be precisely controlled, and the solvent evaporation must be controlled to be uniform when mass production of the polymer hollow particles.

The production of polymer hollow particles using a wet process will be described in more detail as follows.

The method of producing polymeric hollow particles by using a wet process includes the steps of providing swellable particles and a solvent for dispersing the swellable particles instead of providing the swellable particle powder in the microwell as compared with the above- The present invention also provides an expandable particle-containing dispersion comprising the above-mentioned particles.

As the solvent, water or the like is used. The content of the solvent is 1 to 99 parts by weight based on 100 parts by weight of the expandable particles.

A PDMS channel member substrate is bonded to a polydimethylsiloxane (PDMS) substrate having the intaglio pattern to form an integrated device. Through the channel of the PDMS channel member substrate, the expandable particle-containing dispersion can be supplied to the microwell of the PDMS substrate (mold) having the intaglio pattern.

As the mold, a soft mold using a polymer such as polyurethane, polydimethylsiloxane, or a hard mold such as a metal mold may be used. The soft mold can be easily manufactured from a silicon master mold through a simple duplication process.

When the polymer hollow particles are produced by using the dry process, the process and equipment required in the above-mentioned wet process are not required, so that the manufacturing process can be further simplified and facilitated. The use of the dry process has many advantages because a PDMS channel member substrate for supplying the expandable particle-containing dispersion required in the wet process is unnecessary.

According to the dry process, after the expandable particles are sprayed on the microwell of the mold, a taping process, a blowing process, or a process of applying ultrasonic waves with an adhesive force can be performed. The taping process is a process of removing excess particles using a tape material, and it is possible to remove the swelling particles supplied to the microwells excessively even through a blowing process and a process of applying ultrasonic waves. Among them, the taping process can remove excess particles more uniformly than the blowing process and the process of applying ultrasonic waves.

By the above-described taping process, blowing process, or ultrasonic wave applying process, the expandable particles can be appropriately supplied to the microwells of the mold so as to correspond to the desired polymer hollow particles.

The expandable particles were added to the microwells of the mold, And then heat treatment is carried out. In this case, the heat treatment is performed in a temperature range higher than the glass transition temperature of the thermoplastic resin constituting the shell of the expandable particles.

The result of the first step is heat-treated to expand the intumescent pattern of the intaglio pattern.

And the expanded polymeric hollow particles are separated from the substrate according to the second step. After the particles have been expanded in the mold, the expanded polymeric hollow particles are separated from the mold. Ultrasonic waves or blowing or water-soluble tapes are used to separate the polymer hollow particles from the mold.

According to one embodiment of the process for producing a polymeric hollow particle, polymer hollow particles having the form of integral particles, primary particles, or secondary particles can be obtained. The shape of the polymer hollow particles may vary depending on the heat treatment temperature, heat treatment time, and surface treatment.

As the polymer hollow particles, a polymer magnetic particle having a coating film formed of a fluorine-based substance on the particle surface and surface-treated may be used. The polymer hollow particles thus surface-treated are inhibited from aggregating and binding between particles, and thus it is possible to produce a single particle having almost no grain boundary system. Specific examples of the fluorine-based substance include low-molecular substances such as 1,1-difluoroethane.

According to another aspect, there is provided a polymer hollow particle having a monodisperse particle shape and having a density of 0.001 to 1 g / cm < ³ >, which is a monodispersed particle prepared according to the aforementioned manufacturing method and including an expandable core and a thermoplastic polymer shell . The degree of dispersion of the polymer hollow particles is 5% or less.

 The polymer hollow particles according to one embodiment can easily produce particles having various shapes by low-temperature heating and a short-time process. It is possible for the polymer hollow particles according to one embodiment to precisely control the edge of the particle by the change of the temperature and the expansion pressure condition. It is also possible to control the density of the polymer hollow particles by varying the number of particles and degree of expansion. And high high-precision patterns can be realized by high expansion pressure.

According to another aspect, there is provided a composite using the above-described polymer hollow particles.

The composite includes at least one material selected from the group consisting of polymer hollow particles and an electron conductive material, a material having an electromagnetic wave shielding ability, a thermoelectric material, a thermoplastic resin and a thermosetting resin.

According to one embodiment, the at least one material selected from the group consisting of the electron-electron conductive material, the electromagnetic shielding material, the thermoelectrically conductive material, the thermoplastic resin and the thermosetting resin may be included in the coating layer disposed on the surface of the polymer hollow particles. According to another embodiment, at least one material selected from among an electron conductive material, a material having electromagnetic wave shielding ability, a thermoelectric conductive material, a thermoplastic resin and a thermosetting resin can form a complex together with the polymeric hollow particles.

The above-described complex can be used as a filler. And the size of the composite is, for example, 100 to 100,000 nm. The size refers to the average diameter when the composite is spherical, and to the long axis when it is non-spherical.

The composite may include at least one material selected from the group consisting of polymer hollow particles and an electron conductive material, a material having an electromagnetic wave shielding property, a thermoelectric material, a thermoplastic resin, and a thermosetting resin.

The material may be selected from the group consisting of, for example, Al, Ag, Au, Cu, Ni, Sn, Pt, Si, Ge, In, Sb, Pb, Bi, Cd, Zn, Mo, At least one.

The material may be selected from, for example, CuO, Cu ₂ O, SiO ₂ , Fe ₂ O ₃ , Fe ₃ O ₄ , CaO, B ₂ O ₃ , B ₂ O, B ₆ O, Al ₂ O ₃ , BeO, ZnO, MgO, SiC, AlN, SiN, BN, BCN, Ti _x C _y (titanium carbide), Ti _x N _y (titanium nitride), Ti _x C _y N _z (titanium carbide nitride), Carbon Nanotube At least one selected from the group consisting of graphite, graphene, diamond, fullerene, carbon black and combinations thereof.

The thermoplastic resin and the thermosetting resin may all be used as long as they are commonly known in the art.

The composite can be manufactured in various shapes such as particle shape, structure, composition and the like, so that density, electric conductivity, electromagnetic wave shielding property, heat conduction property, and the like can be efficiently controlled. Therefore, these composites can be used for biochemicals, fused materials, and building materials by using low density, large surface area, and surface characteristics.

When the polymer hollow particles according to one embodiment and the composite containing the same are applied to a biomaterial, the hollow polymer particles are separated from the spherical particles and subjected to application of hollow particles as well as anisotropic particles. Particles can be produced. In addition, when the polymer hollow particles according to one embodiment and the composite containing the hollow polymer particles are applied to building materials, it is possible to overcome the limit of the high-density filling of the spherical particles and to lighten the construction and the exterior material from the filling thereof.

In the case where the polymer hollow particles according to one embodiment and the composite containing the same are applied to a photonic crystal material, the anisotropic particles can realize a photonic crystal structure not existing in a conventional form, and thus, a next generation photoelectric device can be manufactured. In addition, the polymer hollow particles and the complex according to one embodiment are nanoparticles that can be used in various fields such as optical materials, intelligent drug delivery and release systems, small electronic circuits, biosensors, catalyst supports, and the like.

Hereinafter, specific embodiments will be described. It should be understood, however, that the embodiments described below are intended to be illustrative or for the purpose of illustration only and are not intended to be limiting.

Example  1: Preparation of polymer hollow particles

Substrates containing intaglio patterns were fabricated using photolithographic processes and PDMS (poly (dimethylsiloxane)), a thermosetting silicone polymer.

A photosensitive resin is coated on a silicon substrate, ultraviolet rays are selectively irradiated through a photomask having a rectangular pattern having a width of 20 m and a depth of 20 m, and a portion not irradiated with ultraviolet rays is removed through a developer, .

A PDMS substrate (PDMS substrate A) having an intaglio pattern was prepared by applying PDMS, which is a thermosetting polymer, to the mold obtained as described above and curing at 80 DEG C for 24 hours.

A PDMS channel member substrate was bonded to the PDMS substrate having the intaglio pattern to manufacture a device. The expandable particle-containing dispersion obtained by the following procedure was supplied to the microwell of the PDMS substrate A through the channel of the PDMS channel member substrate. The PDMS channel member substrate was subjected to an oxygen plasma treatment for about one minute to induce formation of a hydrophilic chemical group hydroxyl group on the surface of the PDMS channel member substrate. It was possible to uniformly and well supply the PDMS substrate A to the microwells of the PDMS substrate A through the channel of the PDMS channel member substrate through the surface treatment such as the oxygen plasma.

The above expandable particle-containing dispersion was obtained by dispersing two expandable particles (461DU, SEKISUI) having a diameter of about 10 μm in water. The content of expandable particles in this expandable particle-containing dispersion was 1% by weight.

The expandable particle is an expandable particle powder comprising an isobutane core and a vinylidene chloride-co-acrylonitrile-co-methyl methacrylate copolymer shell. The mixing weight ratio of vinylidene chloride, acrylonitrile and methyl methacrylate repeating units in the vinylidene chloride-co-acrylonitrile-co-methyl methacrylate copolymer was (25:35:40 by weight).

The PDMS channel member substrate was separated from the resultant product obtained by the above procedure, and the PDMS substrate (mold lid) in a closed state in which no channel existed was combined and integrated. The integrated product was placed in a hot stage and heated to 100 ° C at a rate of 10 ° C per minute to expand the expandable particles to produce expanded polymer hollow particles.

A PDMS substrate having no channel located at the upper end was separated from the device having the expanded particles made through the above-described manufacturing process.

A water-soluble tape (Clover yarn) was attached to the upper portion of the intaglio PDMS substrate having the expanded particles, and then it was gradually removed from the mold. Thereafter, the expanded polymeric hollow particles were separated by dissolving the water-soluble tape having the expanded particles in water to obtain the desired quadrangle monodispersed polymer hollow particles.

Example  2

Place 0.1 g of inflatable particles on a microwell (20 μm in depth and 20 μm in width) of a PDMS substrate (mold) (PDMS substrate A) with intaglio pattern obtained according to Example 1) Particles were filled into the microwells of the mold by rubbing in one direction through a rubbing process using a PDMS block of < RTI ID = 0.0 > Then, a conventional 3M scotch tape was attached onto the particle-filled mold and then peeled off to remove excess particles. The above process was repeated three times to prepare a mold filled with a minimum of particles.

As the expandable particles, an expandable particle powder comprising an isobutane core and a vinylidene chloride-co-acrylonitrile-co-methyl methacrylate copolymer shell was used. The blend weight ratio of vinylidene chloride, acrylonitrile and methyl methacrylate in the vinylidene chloride-co-acrylonitrile-co-methyl methacrylate copolymer was (25:35:40 parts by weight).

A PDMS substrate (mold lid) in a clogged state in which no channel exists is bonded to the resultant product obtained through the above process to integrate. After placing it in a hot stage, it was heated to 100 ° C at a rate of 10 per minute to expand the expandable particles to produce expanded polymer hollow particles.

A water-soluble tape (Clover yarn) was attached to the upper portion of the intaglio PDMS substrate having the expanded particles, and then it was gradually removed from the mold. Thereafter, the expanded polymeric hollow particles were separated by dissolving the water-soluble tape having the expanded particles in water to obtain the desired quadrangle monodispersed polymer hollow particles.

Example  3: Preparation of Polymeric Hollow Particle / Epoxy Resin Composite

The epoxy resin and the curing agent were poured into a mold, and then the mixture was stirred at 1000 RPM for 5 minutes to prepare an epoxy mixture (epoxy melt) uniformly mixed with an epoxy resin and a curing agent. .

10 g of the polymer hollow particles prepared according to Example 1 were mixed with 10 g of the epoxy mixture (epoxy melt) obtained according to the above procedure, and the mixture was placed in a co-rotating centrifugal mixer, stirred at 1000 rpm for 5 minutes, Particle / epoxy composite.

Example  4: Preparation of Polymeric Hollow Particles / Epoxy Resin Composites

10 g of the polymer hollow particles prepared according to Example 1 were acid-treated to remove impurities on the surface to prepare first polymer hollow particles.

Electroless deposition of a composition comprising ₇ ml of an aqueous copper sulfate solution (CuSO ₄ 5H ₂ O), 0.7 ml of a reducing agent, formaldehyde (HCHO) and 2.8 g of complexing agent ethylenediaminetetraacetic acid (C ₁₀ H ₁₆ N ₂ O ₈ ) Copper solution was prepared, and the first polymer hollow particles were immersed in the electroless copper solution for 120 minutes and stirred to prepare polymer hollow particles having a copper coating film disposed thereon.

Separately, an epoxy resin and a curing agent were blended at a compounding ratio calculated in an equivalence ratio, and the mixture was poured into a mold. Then, the mixture was stirred in a centrifugal mixer at 1000 rpm for 5 minutes to prepare an epoxy melt in which an epoxy resin and a curing agent were uniformly mixed.

10 ml of the polymer hollow particles in which the copper coating film was disposed was mixed with 10 g of the mixed epoxy melt, and the mixture was placed in a co-rotating centrifugal mixer and mixed at 1000 rpm for 5 minutes to prepare a polymer hollow particle / epoxy composite.

Example  5

The device manufactured by integrating the PDMS channel member obtained in a flat state on the PDMS substrate having the decorating pattern according to Example 1 was integrated into the hot stage and then heated to 100 ° C at a rate of 20 ° C per minute Was carried out in the same manner as in Example 1 except that the heat treatment temperature was changed to 90 캜 to prepare spherical polymer hollow particles.

Example  6

The device manufactured by integrating the PDMS channel member obtained in a flat state on the PDMS substrate having the decorating pattern according to Example 1 was integrated into the hot stage and then heated to 100 ° C at a rate of 20 ° C per minute The procedure of Example 1 was repeated except that the heat treatment temperature was changed to 110 ° C to expand the expandable particles to prepare hollow polymer hollow particles having a sharp edge.

Example  7

A line nano pattern (line width: 600 nm) is formed on a PDMS (mold lid) in a closed state in which no channel exists and the shape of the microwell is changed to a circular shape in the substrate on which the intaglio pattern is formed, Was prepared in the same manner as in Example 1 to prepare polymer hollow particles.

Example  8

Polymer hollow particles were prepared in the same manner as in Example 7 except that two expandable particles were arranged in a microwell of a substrate on which a decoratched pattern was formed.

Example  9

Polymer hollow particles were produced in the same manner as in Example 1 except that a line nano pattern was formed on a PDMS (mold lid) in a closed state in which no channel existed and one expandable particle was disposed in the microwell .

Example  10

The polymer hollow particles were prepared in the same manner as in Example 9, except that two expandable particles were arranged in a microwell of a substrate on which a decorrelated pattern was formed.

Example  11

Except that a line nano pattern is formed on a PDMS (mold lid) in a closed state in which no channel exists and the shape of the microwell is changed to a quadrangle in the substrate on which the intaglio pattern is formed and one expandable particle is arranged in the microwell Was carried out in the same manner as in Example 1 to prepare polymer hollow particles.

Example  12

Polymer hollow particles were prepared in the same manner as in Example 11, except that two expandable particles were arranged in a microwell of a substrate on which a decorrelated pattern was formed.

Example  13

Except that a line nano pattern was formed in a PDMS (mold lid) in a closed state in which no channel existed and the shape of the microwell was changed to a pentagon in the substrate on which the intaglio pattern was formed and one expandable particle was arranged in the microwell Was carried out in the same manner as in Example 1 to prepare polymer hollow particles.

Example  14

Except that the nanopattern of the cover or the nano pattern of the mold was changed to a hole pattern (hole diameter: about 600 nm), and one expandable particle was arranged in the microwell of the substrate on which the decorativeness pattern was formed, To prepare polymer hollow particles.

Example  15-16

The resultant integrated product was placed in a hot stage and heated to 100 DEG C at a rate of 0.1 DEG C per minute and at a rate of 20 DEG C per minute to expand the expandable particles to produce expanded polymer hollow particles. 1 to prepare polymer hollow particles.

Example  17-18

The resultant integrated product was placed in a hot stage and heated to 100 DEG C at a rate of 0.1 DEG C per minute and at a rate of 20 DEG C per minute to expand the expandable particles to produce expanded polymer hollow particles. 2 to prepare polymer hollow particles.

Comparative Example  One

10 ml of polystyrene particles (40 μm in diameter) were mixed with 10 ml of the epoxy mixture (epoxy fusion material) of Example 3, and then mixed in a co-centrifugal mixer at 1000 rpm for 5 minutes to prepare a polymer particle / epoxy composite.

Comparative Example  2

In order to compare the amount of copper particles actually present, 0.1 ml of common copper particles (10 μm in diameter) identical to the amount of copper present on the surface of the polymer-coated hollow particle of copper-coated form prepared according to Example 4 The mixture was mixed with 10 ml of the mixed epoxy resin, and the mixture was placed in a co-centrifugal mixer and mixed at 1000 RPM for 5 minutes to prepare a polymer particle / epoxy composite.

Comparative Example  3

Nanoparticles were prepared using a replica mold having a microwell of a regular triangular cross section having a depth of 50 mu m and a length of 150 mu m. PEG-DA (polyethylene glycol diacrylate, Mw = 575, Sigma-Aldrich Chemicals) was added to the microwell of the replica mold. A replica mold filled with PEG-DA in a vacuum chamber was left for 5 minutes to remove air bubbles formed in the microwell. Excess PEG-DA filling the microwell was re-collected using a capillary rig by tilting the replica mold or using a pipette tip to fill the boundary of the microwell with PEG-DA. Then, 2,2-diethoxyacetophenone (DEAP), a photoinitiator, was added to cover the top surface of the microwell with a solvent containing 1-5 vol%. From the point of time when the solvent was added, a change in image with time was observed using a reversed-phase microscope equipped with a CCD camera (Coolsnap, Photometrics, USA) (TE2000, Nikon, Japan). 20 minutes after the addition of the solvent, an ultraviolet ray of 365 nm was irradiated for 2 minutes using an 8 W compact UV lamp (Spectronics Corp., Westbury, NY). After UV irradiation, the replica mold was soaked in IPA (isopropyl alcohol) to recover the polymer microparticles. Examples of the solvent include PDMS oil (Dow Corning) or Fluorinert ^? FC-40 (Sigma) was used.

Evaluation example  1: Specific gravity

The specific gravity of the composite obtained according to Example 3 and Comparative Example 1 was measured and the results are shown in Table 1 below. The specific gravity of the composite was measured based on the apparent specific gravity method.

Example 3 Comparative Example 1 Specific gravity (g / cm ³ ) 0.08 1.10

Referring to Table 1, it can be seen that the composite according to Example 3 is hollow particles having a very large number of pores, and thus the specific gravity is significantly reduced as compared with Comparative Example 1

Evaluation example  2: Electrical Conductivity and Thermal Conductivity

The electrical conductivity and thermal conductivity of the composite prepared in Example 4 and the composite prepared in Comparative Example 2 were compared.

The composites of Example 4 and Comparative Example 2 were processed to a thickness of 2 mm and the electrical conductivity and thermal diffusivity were measured based on the method of ASTM F 390 and ASTM E 1461-92, respectively. The thermal diffusivity was converted to the thermal conductivity through the product of density and specific heat, and the values of electrical conductivity and thermal conductivity are shown in Table 2 below.

division Example 4 Comparative Example 2 Electrical Conductivity (S / cm) 6.0 × 10 ² 1.0 x 10 ^-6 Thermal conductivity (W / mK) 4.0 0.5

Referring to Table 2, the electrical conductivity and the thermal conductivity of the copper-coated shape-controlled polymer hollow particle / epoxy composite prepared according to Example 4 of the present invention were measured by an efficient conduction effect by the electricity and heat transfer path made of copper Epoxy composite exhibited remarkably excellent electrical conductivity and thermal conductivity as compared with the copper / epoxy composite prepared by Comparative Example 2.

Evaluation example  3: Optical microscope

1) Examples 1, 5-6

The polymer hollow particles produced according to Examples 1 and 5-6 were analyzed using an optical microscope. The results of the analysis are shown in Figs. 2A to 2C. DM-2500 from Leica was used as an optical microscope.

Referring to this, when the expandable particles were supplied to the microwells and heated to 90 ° C, unexpanded microparticles were observed as shown in FIG. Referring to FIG. 2B, when the expandable particles were supplied to the microwells and heated to 100 DEG C, microparticles having a rounded edge were observed.

Microbubbles with sharp edges were observed when the expandable particles were fed into the microwells and heated to 110 ° C. When the expandable particles were supplied to the microwell and heated to 120 ° C, the microbubble rupture structure was observed. From this, it can be seen that the shape of the polymer hollow particles can be controlled according to the heat treatment temperature of the expandable particles.

As described above, it is easy to control the shape of the edge such that the polymer hollow particles have round edges or sharp edges when the heat treatment temperature is changed as in Examples 1 and 5-7. On the other hand, in the case of performing the process according to Comparative Example 3, in order to control the shape of the edge of the desired particle, the shape of the mold must be controlled, which may increase the manufacturing cost and restrict the shape of the particle to be implemented.

2) Examples 8-14

The polymer hollow particles prepared according to Examples 8-14 were observed under an optical microscope.

Optical micrographs of the polymer hollow particles prepared according to Examples 8-14 are shown in Figs. 3A-3H, respectively. FIG. 3H is an enlarged view of the square area of FIG. 3G.

Referring to this, the polymer hollow particles of Examples 7-13 can be formed into a line pattern by changing the nanopattern of the microwell of the mold and the nanopattern of the cover to form a line pattern on the surface thereof, Could know.

3) Example 14

The polymer hollow particles prepared according to Example 14 were observed with an optical microscope.

Optical micrographs of the polymer hollow particles prepared according to Example 14 are shown in FIGS. 4A and 4B, respectively. 4B is an enlarged view of the square area of FIG. 4A.

Referring to this, it can be seen that the polymer hollow particles of Example 14 can form a hole pattern on the surface of the mold by changing the nano pattern of the microwell of the mold and the nano pattern of the cover into a hole pattern, there was.

Evaluation example  4: Observation of limited expansion behavior

In order to investigate the limited expansion behavior when prepared according to Example 1, a real time tracking process was confirmed.

As a result, the shape of the polymer hollow particles finally determined according to the shape of the microwell of the mold was determined, and the expansion ratio of each particle was found to increase with time.

Evaluation example  5: Size distribution characteristic of particle

The size distribution characteristics of the polymer hollow particles prepared according to Example 1-2 and the polymer particles prepared according to Comparative Example 3 were evaluated.

As a result of the evaluation, the polymer hollow particles produced according to Example 1-2 exhibited a monodispersed particle shape having the same particle size. On the other hand, the polymer particles prepared according to Comparative Example 3 exhibited a multi-dispersed particle shape having different particle sizes unlike the polymer hollow particles of Example 1-2.

The size distribution characteristics of the polymer hollow particles produced in accordance with Examples 15-18 were also evaluated. As a result, the polymer hollow particles produced according to Examples 15-18 exhibited monodispersed particle shapes having the same particle size as the polymer hollow particles prepared according to Example 1-2.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Do.

10: Substrate 11 on which a pattern with intonation is formed 11: Microwell
12: expandable particles 13: polymer hollow particles

Claims (15)

A first step of providing at least one expandable particle containing an expandable core and a thermoplastic polymer shell comprising a blowing agent in a substrate having a pattern engraved;
A second step of removing excess expandable particles from the result of the first step;
A third step of heat-treating the resultant product of the second step to swell the intumescent patterned expandable particles; And
And a fourth step of separating the expanded polymeric hollow particles from the substrate according to the third step. The method according to claim 1,
The expandable particles provided in the pattern engraved in the first step are provided as monodisperse or polydisperse particles, and the polymer hollow particles obtained in the fourth step are obtained by preparing polymer hollow particles which are monodispersed polymer hollow particles Way. The method according to claim 1,
Wherein the first step comprises:
One or more expandable particles comprising the expandable core and the thermoplastic polymer shell are mixed with a solvent to provide a substrate having a textured pattern or
A method for the production of polymeric hollow particles which provides one or more swellable particles comprising an expandable core and a thermoplastic polymer shell dry. The method according to claim 1,
Wherein the heat treatment in the third step is carried out at 50 to 170 ° C. The method according to claim 1,
Wherein the foaming agent comprises a non-fluorinated hydrocarbon compound having a low boiling point which becomes a gaseous phase at a temperature lower than the softening point temperature of the thermoplastic resin of the thermoplastic resin polymer shell. The method according to claim 1,
In the thermoplastic polymer shell of the expandable particles, the thermoplastic resin is a polymer obtained from a polymerizable monomer or a reaction product of a polymerizable monomer and a crosslinking agent,
The polymerizable monomer may be at least one selected from the group consisting of nitrile monomers, carboxylic acid monomers, (meth) acrylic acid ester monomers, acrylamide monomers, maleimide monomers, vinyl ether monomers, vinyl ketone monomers, aromatic divinyl monomers, N- Based monomer, a vinyl-based monomer, a halogenated vinyl-based monomer, and combinations thereof,
The crosslinking agent may be at least one selected from the group consisting of allyl methacrylate, triacryloformate, triallyl isocyanate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (Meth) acrylate, 1, 10-decanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di Acrylate, trimethylolpropane trimethacrylate, glycerol dimethacrylate, dimethylol-tricyclodecane diacrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, neo Pentyl glycol acrylic acid benzoic acid ester, trimethylolpropane acrylic acid benzoic acid ester, 2-hydroxy-3-acryloyloxypropyl methacrylate Butyl-2-ethyl-1,3-propanediol diacrylate, and combinations thereof. The polymerizable composition according to claim 1, wherein the polymerizable monomer is selected from the group consisting of poly Wherein the hollow polymer particle has an average particle diameter of not more than 100 nm. The method according to claim 1,
The thermoplastic resin of the thermoplastic polymer resin shell of the expandable particles is preferably a thermoplastic resin having a first (meth) acrylic repeating unit, a second repeating unit of a nitrile and a second repeating unit of a (meth) 3 repeating units,
The content of the first (meth) acrylic repeating unit is 10 to 50% by weight based on the total amount of the repeating units, the content of the second repeating unit is Wherein the content of the third repeating unit is in the range of 30 to 80 wt% based on the total content, and the content of the third repeating unit is in the range of 10 to 50 wt%. The method according to claim 1,
The blowing agent in the expandable particles may be at least one selected from the group consisting of propane, propylene, butene, n-butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, octane, Dicarbonamide, and combinations thereof. ≪ Desc / Clms Page number 24 > The method according to claim 1,
Wherein a line or a hole pattern is formed on the substrate having the engraved pattern so that a line or a hole pattern is formed on at least one surface of the polymer hollow particle. The method according to claim 1,
The specific gravity of the polymer hollow particles obtained according to the above production method is 0.001 to 1 g / cm < ³ >, which is a monodisperse type particle. 10. A polymer hollow particle having a specific gravity of from 0.001 to 1 g / cm < ³ >, the monodispersed particle comprising an expandable core and a thermoplastic polymer shell produced by the manufacturing method of any one of claims 1 to 10. 12. The method of claim 11,
Wherein the polymer hollow particles have a degree of dispersion of 5% or less. 10. A polymeric hollow particle having a specific gravity of 0.001 to 1 g / cm < ³ >, which is a monodisperse type particle prepared by the manufacturing method of any one of claims 1 to 10 and comprising an expandable core and a thermoplastic polymer shell; And
A composite comprising at least one material selected from an electron conductive material, a material having an electromagnetic shielding ability, a thermoelectrically conductive material and a polymer resin. 14. The method of claim 13,
The composite may comprise polymeric hollow particles; And a coating film containing at least one material selected from an electron conductive material disposed on the surface of the polymer hollow particles, a material having an electromagnetic shielding property, a thermoelectric material, and a polymer resin, or
Wherein the composite has a structure in which polymer hollow particles and at least one material selected from the group consisting of an electron conductive material, a material having an electromagnetic shielding property, a thermoelectrically conductive material, and a polymer resin are combined. 14. The method of claim 13,
Wherein the polymer hollow particles have a degree of dispersion of 5% or less.

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