KR102131301B1 - Polymer hollow particle, preparing method thereof, and composite comprising the polymer hollow particle - Google Patents

Abstract

A first step of providing at least one expandable particle containing an expandable core comprising a blowing agent and a thermoplastic polymer shell to a substrate having an intaglio pattern; A second step of removing excess expandable particles from the result of the first step; A third step of expanding the expandable particles of the engraved pattern by heat-treating the result of the second step; And a fourth step of separating the polymer hollow particles, which have been expanded according to the third step, from the substrate, and a low specific gravity, monodisperse polymer having various shapes manufactured according to the manufacturing method. Hollow particles and composites comprising the same are disclosed.

Description

Polymer hollow particles and their manufacturing method and composite comprising the same {Polymer hollow particles, preparing method thereof, and composite comprising the polymer hollow particles}

As for the polymer hollow particle, a method for manufacturing the same, and a composite comprising the same, more specifically, a method for manufacturing a hollow polymer particle using expandable particles and a polymer hollow particle manufactured according to the manufacturing method and a composite comprising the same are presented .

Polymer particles are widely used in various fields such as sustained-release preparations, optical materials, and chromatography media. Recent studies have been conducted on the use of polymer particles as a building block for the production of complex structures. In these applications, the physical, chemical properties of polymer particles such as structure, size, shape, porosity, surface charge, hydrophilicity, and hydrophobicity affect the function of the particles, introducing complexity into the structure of the particles and uniformly It is very important to control. In addition, the design of polymer particles with various shapes and physicochemical properties can further expand their applications.

As a method of manufacturing polymer microparticles with controlled shape and shape, manufacturing methods such as microfluidic systems, control of emulsion polymerization, and phase separation are known. However, with such a manufacturing method, it is not easy to control the density characteristics of particles, and the manufacturing process itself is complicated, and thus improvement is required.

One aspect is to provide a method for producing hollow polymer particles having various shapes using particles that expand by heat.

Another aspect is to provide hollow polymer particles having a monodispersity and being produced by the above-described manufacturing method.

Another aspect is to provide a composite containing the above-mentioned polymer 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 an intaglio pattern;

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

A third step of expanding the expandable particles of the engraved pattern by heat-treating the result of the second step; And

A method of manufacturing a hollow polymer particle comprising a fourth step of separating the polymer hollow particle having been expanded according to the third step from the substrate is provided.

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

According to the other side

It is manufactured according to the above-described manufacturing method, and is a monodispersed particle comprising an expandable core and a thermoplastic polymer shell, and a polymer hollow particle having a specific gravity of 0.001 to 1 g/cm ³ is provided.

According to another aspect, the polymer hollow particles; And an electronic conductive material, a material having an electromagnetic wave shielding performance, a thermal electronic conductive material, or a polymer resin.

The composite is a polymer hollow particle; And disposed on the surface of the polymer hollow particles, has a structure containing a coating film containing at least one material selected from an electron conductive material, a material having an electromagnetic wave shielding performance, a thermal electron conductive material and a polymer resin, or the composite is a hollow polymer It has a structure in which one or more materials selected from particles, electron conductive materials, materials having electromagnetic wave shielding performance, thermal electron conductive materials, and polymer resins are combined.

According to one aspect, polymer hollow particles having various shapes may be manufactured using expandable particles expanded by heat. When the polymer hollow particles are supplied with expandable particles in a pattern of various shapes and heated, the polymer particles expand according to the shape of the pattern and the shape is controlled, so the shape is easily controlled and has a low specific gravity.

Figure 1a is for explaining the manufacturing process of the monodisperse polymer hollow particles according to an embodiment.
1B is a view for explaining the properties of the hollow polymer particles according to one embodiment.
1C to 1F are optical micrographs of polymer hollow particles according to one embodiment.
2A to 2C are optical micrographs of the polymer hollow particles prepared according to Examples 1, 5 and 6.
3A to 3G are optical micrographs of polymer hollow particles prepared according to Examples 8-14.
3H is an enlarged view of the square area of FIG. 3G.
4A is an optical micrograph of polymer hollow particles prepared according to Example 14.
4B is an enlarged view of the square area of FIG. 4A.

Hereinafter, a polymer hollow particle according to an embodiment, a method of manufacturing the same, and a composite containing the polymer hollow particle 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 an intaglio pattern;

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

A third step of expanding the expandable particles of the engraved pattern by heat-treating the result of the second step; And

A method of manufacturing a hollow polymer particle comprising a fourth step of separating the polymer hollow particle having been expanded according to the third step from the substrate is provided.

When the above-described manufacturing method is used, it is possible to easily produce hollow polydispersed polymer particles having various shapes and low specific gravity by using expandable particles having properties of expanding by heat.

The expandable particles provided in the intaglio pattern in the first step are one or more of monodisperse or polydispersed type, for example 1 to 1000, for example 1 to 500, for example 1 to Provided in 100 ranges, it is possible to control the density and morphology of the polymer hollow particles having monodispersed expansion. As described above, even if a polydispersed type rather than a monodisperse type is used as the expandable particle as a starting material, the monodisperse polymer hollow particle can be produced as a final target. These hollow polymer particles are uniform in size and have virtually no aggregation between particles.

When the diameter distribution of the polymer hollow particles is measured by dynamic light scattering, the particle diameter is well controlled so that the particle size has a dispersion of 5% or less, for example 1%, for example 0.1% or less, for example For example, the particles are monodisperse particles having a uniform content of 0.01% or less, for example, 0.0001 to 0.01%.

In the first step, at least one expandable particle comprising the expandable core and the thermoplastic polymer shell is mixed with a solvent to be provided on a substrate having a wetly engraved pattern, or at least one expandable particle comprising the expandable core and the thermoplastic polymer shell Can be provided dry. Here, dry means a rubbing method, a spraying method, or the like.

In the third step, the heat treatment is performed in a range of 50 to 170°C, for example, 90 to 120°C, for example, 100 to 120°C. The heating rate during heat treatment is 0.1 to 20°C/min, for example, 10°C/min. When the heat treatment temperature and the temperature increase rate are in the above range, expansion of the expandable particles is smoothly performed, so that the polymer hollow particles with expansion having the desired polymer shell thickness can be obtained. In particular, when the heating rate is within the above-described range, it is possible to maintain expandable particles without structural defects or breakage of the core and shell. As a result, the true specific gravity of the polymer hollow particles becomes larger than expected, or the expansion magnification is not controlled as desired, thereby preventing thermal expansion properties from deteriorating. A substrate with an intaglio pattern is, for example, a substrate with microwells.

If the expandable particles are provided to the microwell of the mold in the form of an aqueous dispersion of expandable particles, unnecessary solvent may be removed in the heat treatment process described above. In addition, expansion proceeds in the heat treatment process, and the heat treatment time may vary, for example, in the range of 1 second to 24 hours.

The substrate on which the intaglio pattern is formed can be prepared using a photoetching process and a polydimethylsiloxane (PDMS), which is a thermosetting silicone polymer.

After coating the photosensitive resin on the silicon substrate, ultraviolet rays are selectively irradiated through a photomask having patterns of various circular, triangular, square, pentagonal, hexagonal, etc. having a predetermined width and depth, and the portion that is not irradiated with ultraviolet rays When removed through the developer, a mold having a desired pattern can be obtained.

After applying the thermosetting polymer PDMS to the mold obtained as described above and curing it at a temperature of 60 to 90° C. for 10 to 30 hours to separate it from the silicon substrate, it is exposed under an oxygen atmosphere to induce the formation of a hydrophilic chemical group on the surface. A PDMS substrate having an intaglio pattern in a multidirectional shape was obtained. The channel member is manufactured by thermal curing the PDMS applied above.

A device is manufactured by combining PDMS channel members obtained in a flat state on a PDMS substrate having various types of engraved patterns obtained from the above and integrating them.

The size of the engraved pattern is not particularly limited, and depends on the size of the desired polymer hollow particle. The shape of the expanded polymer hollow particles can be controlled by controlling the shape of the intaglio pattern in the thickness direction.

The engraved pattern defines, for example, the length of one side of the plane as A and the number of sides as N, and N changes in the range of 1 to 100, so that when all sides of A are the same, the shape of the expanding particles is The shape of the expandable particles can be varied in an isotropic shape.

The length of one side on the plane of the engraved pattern is defined as A, and the number of sides is defined as N, and N is changed in a range of 1 to 100, so that when all sides of A are not the same, the shape of the expanding particles is determined. It is possible to use expanding particles that deform into an anisotropic shape.

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

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

In the manufacturing method of the polymer hollow particle according to the embodiment, the shape of the mold may be variously manufactured according to the shape of the desired polymer hollow particle such as a circle, a square, and a rectangle.

Polymer hollow particles according to one embodiment is easy to control the shape as desired as shown in Figure 1b (complexity: see #1 and Figure 1c). In addition, the polymer hollow particle of the present invention can control the heat treatment temperature and the like to round or sharply control the edge (see complexity: #2 and FIG. 1D ). And as shown in Figure 1c, the polymer hollow particles can control the number of particles as desired, such as 1, 2, 3 particles, etc. (see complexity: #3 and 1e). It may have the form of a one-body particle, a primary particle or a secondary particle. Secondary particles are aggregates of primary particles. When the polymer hollow particles are integral particles, there are almost no grain boundaries in the particles.

Surface treatment may be performed on the hollow polymer particles according to one embodiment to prevent aggregation and binding of the particles. The surface treatment is, for example, coating a fluorine-based material. Here, as the fluorine-based material, a low molecular material such as 1,1-difluoroethane is used.

The polymer particles of the present invention can form patterns such as holes and lines on their outer surfaces (top, bottom, and side surfaces) as desired (see complexity: #4. and FIG. 1F).

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

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

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

The polymer hollow particles according to one embodiment have large pores therein by expansion, and may be mixed and used as a filler in a polymer substrate to apply as a structure requiring low specific gravity. When the polymer hollow particle of the present invention is used as a filler, it is easy to control various properties such as density, transparency, refractive index, sound insulation, and insulation of a product as desired.

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

Examples of the nitrile-based monomer include acrylonitrile, methacrylonitrile, a-chloracrylonitrile, a-ethoxyacrylonitrile, and fumaronitrile. And the carboxylic acid-based 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; Methyl (meth)acrylate, ethyl (meth)acrylate, normal butyl (meth)acrylate, isobutyl (meth)acrylate, tertiary butyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl ( Meta) acrylate, benzyl (meth) acrylate, and carboxyethylene acrylate. Examples of the styrene-based monomer, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn -Hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, n-methoxystyrene, p-phenylstyrene, p-chlorstyrene, 3,4-dichlorstyrene, etc. Examples of acrylamide-based monomers include acrylamide, substituted acrylamide, methacrylamide, and substituted methacrylamide. And examples of the maleimide-based monomers include N-phenylmaleimide, N-(2-chlorophenyl)maleimide, N-cyclohexylmaleimide, and N-lauryl maleimide.

Examples of the vinyl ether-based monomer include vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether, and the vinyl ketone-based monomer includes vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone.

Aromatic divinyl monomers include, for example, divinylbenzene and divinyl naphtharene.

(Meth)acrylic acid-based ester monomers are, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate , Propyl (meth)acrylate, n-octyl (meth)acrylate, dodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, 2-chlorethyl (meth) Acrylate, phenyl (meth)acrylate, isobornyl (meth)acrylic

And acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, β-carboxyethyl acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. .

Examples of the N-vinyl-based monomer include N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, and N-vinyl pyrrolidone. And vinyl halide monomers include, for example, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, etc. The crosslinking agent is allyl methacrylate, triacrylic formal, triallyl isocyanate, ethylene glycol di (meth) Acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,4-butanedioldi(meth)acrylate, 1,9-nonanedioldi(meth)acrylate, 1, 10-decanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane trimethacrylate, glycerol dimethacrylate, dimethylol-tricyclodecane Diacrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, neopentyl glycol acrylic acid benzoic acid ester, trimethylolpropanacrylic acid benzoic acid ester, 2-hydroxy-3-acryloyl The group consisting of oxypropyl methacrylate, hydroxypivaranoate neopentyl glycol diacrylate, ditrimethylolpropanetetraacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, and combinations thereof Includes any one selected from. The weight average molecular weight of polyethylene glycol in polyethylene glycol di(meth)acrylate may be 200, 400 or 600.

The blowing agent constituting the core of the expandable particles contains a low-boiling, non-fluorine-based hydrocarbon compound that becomes a gaseous phase below the softening point temperature of the thermoplastic resin of the thermoplastic resin polymer shell.

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

The content of the expandable core is 5 to 30% by weight based on the total weight of the expandable particles. The blowing agent is, for example, propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, normal pentane, normal hexane, isohexane, heptane, octane, petroleum ether, methane halide, tetraalkylsilane, azodica One or more selected from lebonamide is used.

The thermoplastic resin constituting the polymer shell contains, for example, a (meth)acrylic first repeating unit as an essential component, and in addition, a nitrile second repeating unit and the (meth)acrylic first repeating unit and a nitrile second repeating unit. And it may be a terpolymer comprising a third repeating unit having no reactivity.

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

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

The third repeating unit is polyvinyl chloride, N-methylol (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, magnesium mono (meth )Acrylate, zinc mono(meth)acrylate, vinyl glycidyl ether, propenyl glycidyl ether, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl And one or more selected from (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate.

The thermoplastic resin may include 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 acrylonitrile repeating units is 10 to 50% by weight, the content of methyl methacrylate repeating units is 30 to 80% by weight, and the content of vinyl chloride repeating units is 10 to 50% by weight.

When using expandable particles including a polymer shell containing a thermoplastic resin having the above-described composition, it is possible to obtain expanded hollow polymer particles having a desired polymer shell thickness, and after expansion is completed, structural defects of the core and shell (defect) ) Or breakable expandable particles, and has excellent specific gravity and thermal expansion properties of the polymer hollow particles.

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

The microwell of a mold, a substrate having an intaglio pattern, provides one or more expandable particles 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 a microwell without a separate solvent in powder form.

Even if the expandable particles provided to the microwell are of a polydispersed type, the finally obtained polymer hollow particles have a monodispersed particle type with excellent dispersion.

When the polymer hollow particles are manufactured using a wet process, it is necessary to install a mold cover, and the evaporation process of the solvent used when docking the particles and dispersing the particles in the microwell of the mold is essential. In addition, the affinity of the solvent for the mold using the wet process and the surface energy must be precisely controlled and controlled so that the evaporation of the solvent is uniform when mass-producing polymer hollow particles.

Looking in more detail about the case of manufacturing the polymer hollow particles using a wet process as follows.

The method for producing hollow polymer particles by using a wet process, when providing one or more expandable particles to a substrate, contains expandable particles and a solvent for dispersing them instead of providing expandable particle powder to a microwell as compared to the dry manufacturing method described above. The same procedure was carried out except for providing a dispersion containing expandable particles.

Water, etc. are used as the solvent. 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 and integrated on a polydimethylsiloxane (PDMS) substrate having the intaglio pattern to manufacture a device. The dispersion containing the expandable particles may be supplied to the microwell of the PDMS substrate (mold) having an intaglio pattern through the channel of the PDMS channel member substrate.

As the mold, a soft mold using a polymer such as polyurethane or polydimethylsiloxane or a hard mold such as a metal mold may be used. Soft molds can be easily fabricated from a silicon master mold through a simple cloning process.

When the polymer hollow particles are manufactured using a dry process, the process and equipment required in the wet process described above are unnecessary, and thus the manufacturing process may be simplified and easier. The use of a dry process has many advantages since the PDMS channel member substrate for supplying the dispersion containing the expandable particles required in the wet process is unnecessary.

According to the dry process, after spraying the expandable particles to the microwell of the mold, it is possible to perform an adhesive taping process, a blowing process, or a process of applying ultrasonic waves. The taping process is a process of removing excess particles using a tape material, and it is possible to remove excessively supplied expandable particles to the microwell 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 going through the above-described taping process, blowing process or ultrasonic process, it is possible to appropriately supply expandable particles to the desired polymer hollow particles in the microwell of the mold.

After the expandable particles are supplied to the microwell of the mold according to the wet or dry method as described above, heat treatment is performed. At this time, the heat treatment is performed in a temperature range larger than the glass transition temperature of the thermoplastic resin constituting the shell of the expandable particles.

A step of heat-treating the resultant product of the first step is performed to expand the expandable particles of the engraved pattern.

According to the second step, the polymer hollow particles having been expanded are separated from the substrate. After the particles have been expanded in the mold, the expanded polymer hollow particles are separated from the mold. When separating the polymer hollow particles from the mold, ultrasonic waves are used, or a blowing or water-soluble tape is used.

According to the method for manufacturing polymer hollow particles according to one embodiment, it is possible to obtain polymer hollow particles having the form of integral particles, primary particles, or secondary particles. 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 coating film formed of a fluorine-based material on the surface of the particles may be used to treat the polymer hollow particles. Thus, the surface-treated polymer hollow particles can suppress aggregation and binding between particles, thereby making it possible to produce single particles with little grain boundaries. Specific examples of the fluorine-based material include low molecular materials such as 1,1-difluoroethane.

According to another aspect, it is prepared according to the above-described manufacturing method and is a monodisperse type particle comprising an expandable core and a thermoplastic polymer shell, and a polymer hollow particle having a monodisperse type particle form having a density of 0.001 to 1 g/cm ³ is provided. . The dispersion degree of the hollow polymer particles is 5% or less.

Polymer hollow particles according to one embodiment can be easily produced particles having various forms by low-temperature heating and short-time process. It is possible for the polymer hollow particle according to one embodiment to precisely control the edge of the particle by changing temperature and expansion pressure conditions. In addition, it is possible to control the density of the hollow polymer particles by varying the number of particles and the degree of expansion. In addition, a high-precision pattern can be realized by a high expansion pressure.

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

The composite includes at least one material selected from polymer hollow particles and electron conductive materials, materials having electromagnetic wave shielding performance, thermoelectroconductive materials, thermoplastic resins, and thermosetting resins.

According to one embodiment, one or more materials selected from the electron-electro-conductive material, a material having electromagnetic wave shielding performance, a thermo-electro-conductive material, a thermoplastic resin, and a thermosetting resin may be included in a coating film disposed on the surface of the polymer hollow particle. According to another embodiment, at least one material selected from an electron conductive material, a material having electromagnetic wave shielding performance, a thermoelectroconductive material, a thermoplastic resin, and a thermosetting resin may form a composite with polymer hollow particles.

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

The composite may include one or more materials selected from polymer hollow particles and electron conductive materials, materials having electromagnetic wave shielding performance, thermoelectroconductive materials, thermoplastic resins, and thermosetting resins.

The material is selected from the group consisting of, for example, Al, Ag, Au, Cu, Ni, Sn, Pt, Si, Ge, In, Sb, Pb, Bi, Cd, Zn, Mo, W, Ti and combinations thereof. It can be at least one.

The material is, for example, CuO, Cu ₂ O, SiO, 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 carbon nitride), Carbon Nanotube (CNT) , Graphite (Graphite), graphene (Graphene), diamond (Diamond), fullerene (Fullerene), carbon black (Carbon black) and may be at least one selected from the group consisting of these.

Any of the thermoplastic resins and thermosetting resins can be used as long as they are commonly known in the art.

The composite can be manufactured in various ways such as particle shape and structure, and its composition, and accordingly, density, electrical conductivity, electromagnetic wave shielding characteristics, and thermal conductivity characteristics can be efficiently controlled. Therefore, these composites have low density, large surface area, and control of surface properties, which makes them useful for bio, chemical, fusion materials, and construction materials.

When the polymer hollow particle according to an embodiment and the composite containing the same are applied to a biomaterial, the polymer hollow particle deviates from the limitations of the spherical particle, as well as anisotropic particles as well as functionality for drug delivery and release systems through the application of hollow particles. Particles can be prepared. In addition, when the polymer hollow particle according to an embodiment and the composite including the same are applied to a building material, it is a form that exceeds the limit of the closest filling of the spherical particle, and it is easy to lighten the building and exterior materials from their filling.

When the polymer hollow particle according to one embodiment and the composite including the same are applied to a photonic crystal material, the anisotropic particles can implement a photonic crystal structure of a type that does not exist in the past, and use this to produce a next-generation photoelectric device. In addition, the polymer hollow particles and composites 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, and catalyst supports.

Hereinafter, specific embodiments are presented. However, the examples described below are only intended to be specifically illustrated or described, and are not meant to be limited thereby.

Example 1: Preparation of hollow polymer particles

The substrate including the intaglio pattern was prepared using a photoetching process and a thermosetting silicone polymer PDMS (Poly(dimethylsiloxane)).

After coating the photosensitive resin on the silicon substrate, UV light is selectively irradiated through a photomask having a rectangular pattern having a width of 20 μm and a depth of 20 μm, and a part of the desired pattern is molded by removing the unradiated part through the developer. Was able to get.

PDMS, a thermosetting polymer, was applied to the mold obtained as described above, and cured for 24 hours at a temperature of 80° C. to separate from the silicon substrate to prepare a PDMS substrate (PDMS substrate A) having an intaglio pattern.

The PDMS channel member substrate was combined and integrated on the PDMS substrate having the intaglio pattern to manufacture the device. Through the channel of the PDMS channel member substrate, the dispersion containing the expandable particles obtained according to the following procedure was supplied to the microwell of the PDMS substrate A. Oxygen plasma treatment was performed on the PDMS channel member substrate for about 1 minute to induce the formation of a hydrophilic chemical group, a hydroxyl group, on the surface of the PDMS channel member substrate. Through such a surface treatment such as oxygen plasma, the microwell of the PDMS substrate A can be uniformly well supplied to the dispersion containing the expandable particles through the channel of the PDMS channel member substrate.

The 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 the expandable particles in the dispersion containing the expandable particles was 1% by weight.

The expandable particles are expandable particle powders comprising an isobutane core and a vinylidene chloride-co-acrylonitrile-co-methyl methacrylate copolymer shell. The mixed 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 weight ratio).

The PDMS channel member substrate was separated from the result obtained according to the above process, and the PDMS substrate (mold cover) in a blocked state without a channel was combined and integrated. After the integrated result was placed in a hot stage, it was heated at a rate of 10°C per minute to 100°C to expand the expandable particles to prepare expanded polymer hollow particles.

The PDMS substrate having no channel located at the top was separated from the device having the expanded particles made through the above manufacturing process.

After attaching a water-soluble tape (Clover) to the top of the intaglio PDMS substrate with the particles that had been expanded, they were slowly removed from the mold. Then, the expanded polymer hollow particles were separated by dissolving the water-soluble tape with the expanded particles in water to obtain the desired rectangular monodisperse polymer hollow particles.

Example 2

0.1 g of expandable particles were placed on a microwell (20 μm in depth and 20 μm in width) of a PDMS substrate (mold) (PDMS substrate A) having an 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. Thereafter, a conventional 3M scotch tape was attached to a mold filled with particles and then peeled off to remove excess particles. The above process was repeated 3 times to prepare a mold filled with minimal particles.

As the expandable particles, an expandable particle powder including an isobutane core and a vinylidene chloride-co-acrylonitrile-co-methyl methacrylate copolymer shell was used. The mixed 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).

The PDMS substrate (mold cover) in a blocked state in which no channel is present was combined with the result obtained according to the above process to be integrated. After it was placed in a hot stage, it was heated to 100° C. at a rate of 10 per minute to expand the expandable particles to prepare expanded polymer hollow particles.

After attaching a water-soluble tape (Clover) to the top of the intaglio PDMS substrate with the particles that had been expanded, they were slowly removed from the mold. Then, the expanded polymer hollow particles were separated by dissolving the water-soluble tape with the expanded particles in water to obtain the desired rectangular monodisperse polymer hollow particles.

Example 3: Preparation of polymer hollow particles/epoxy resin composite

After mixing the room temperature curing type epoxy resin and the curing agent at a compounding ratio calculated by the equivalent ratio, pour it into a mold, put it in an idle centrifugal mixer and stir for 5 minutes at 1000 RPM to obtain an epoxy mixture (epoxy melt) uniformly mixed with an epoxy resin and a curing agent. It was prepared.

After mixing 10 g of the polymer hollow particles prepared according to Example 1 with 10 g of the epoxy mixture (epoxy melt) obtained according to the above process, put it in an orbital centrifugal mixer and stir for 5 minutes at 1000 rpm to insert the polymer hollow A particle/epoxy composite was prepared.

Example 4: Preparation of polymer hollow particles/epoxy resin composite

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

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

Separately, the epoxy resin and the curing agent were mixed at a compounding ratio calculated by an equivalent ratio, poured into a mold, and then placed in an idle centrifugal mixer and stirred 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 on which the copper coating film was disposed were mixed with 10 g of the mixed epoxy melt, and then placed in an idle centrifugal mixer and mixed at 1000 rpm for 5 minutes to prepare a polymer hollow particle/epoxy composite.

Example 5

After the PDMS channel member obtained by flattening and integrating the PDMS channel member obtained in a flat state on the PDMS substrate having the intaglio pattern according to Example 1 is placed in a hot stage, it is heated at a rate of 20°C per minute to 100°C. It was carried out according to the same method as in Example 1, except that the heat treatment temperature was changed to 90°C in the process to prepare spherical polymer hollow particles.

Example 6

After the PDMS channel member obtained by flattening and integrating the PDMS channel member obtained in a flat state on the PDMS substrate having the intaglio pattern according to Example 1 is placed in a hot stage, it is heated at a rate of 20°C per minute to 100°C. In the process, except that the heat treatment temperature was changed to 110° C., the same procedure as in Example 1 was carried out to expand the expandable particles to produce triangular polymer hollow particles having sharp edges.

Example 7

The shape of the microwell is circularly changed on the substrate on which a line nano pattern (line width: 600 nm) is formed on the PDMS (mold cover) in which the channel does not exist and an intaglio pattern is formed, and one expandable particle in the microwell It was carried out according to the same method as in Example 1, except that was disposed to produce polymer hollow particles.

Example 8

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

Example 9

Polymer hollow particles were prepared in the same manner as in Example 1, except that a line nano pattern was formed on the PDMS (mold cover) in which the channel did not exist and one expandable particle was disposed in the microwell. .

Example 10

Polymer hollow particles were prepared in the same manner as in Example 9, except that two expandable particles were disposed in the microwell of the substrate on which the intaglio pattern was formed.

Example 11

Line nano pattern is formed on the PDMS (mold cover) in the absence of a channel, and the shape of the microwell is changed to a square on the substrate on which the negative pattern is formed, except that one expandable particle is disposed in the microwell. Was carried out according to the same method 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 disposed in the microwell of the substrate on which the intaglio pattern was formed.

Example 13

A line nano pattern is formed on a PDMS (mold cover) in a closed state where no channel is present, and the shape of the microwell is changed to a pentagon on the substrate on which the negative pattern is formed, except that one expandable particle is disposed in the microwell. Was carried out according to the same method as in Example 1 to prepare polymer hollow particles.

Example 14

The same method as in Example 1, except that the nanopattern of the cover or the nanopattern of the mold was changed to a hole pattern (hole diameter: about 600 nm), and one expandable particle was placed in the microwell of the substrate on which the intaglio pattern was formed. Polymer hollow particles were prepared in accordance with the following procedure.

Example 15-16

After the integrated result was placed in the hot stage, it was heated to a rate of 0.1°C per minute and a rate of 20°C per minute, respectively, to 100°C to expand the expandable particles to prepare expanded polymer hollow particles. It carried out according to the same method as 1 to prepare polymer hollow particles.

Example 17-18

After the integrated result was placed in the hot stage, it was heated to a rate of 0.1°C per minute and a rate of 20°C per minute, respectively, to 100°C to expand the expandable particles to prepare expanded polymer hollow particles. It carried out according to the same method as 2 to prepare polymer hollow particles.

Comparative example One

After mixing 10 ml of polystyrene particles (40 um in diameter) with 10 ml of the epoxy mixture (epoxy fusion) of Example 3, it was put in a revolutionary centrifugal mixer and mixed for 5 minutes at 1000 rpm to prepare polymer particles/epoxy composites.

Comparative example 2

To compare the amount of copper particles actually present, 0.1 ml of conventional copper particles (diameter 10 um) equal to the amount of copper present on the surface of the controlled polymeric hollow particle prepared in accordance with Example 4 After mixing with 10 ml of the mixed epoxy fusion, it was put into an idle centrifugal mixer and mixed for 5 minutes at 1000 RPM to prepare a polymer particle/epoxy composite.

Comparative example 3

Nanoparticles were prepared using a replica mold having a microwell having an equilateral triangle with a depth of 50 μm and a length of 150 μm on one side. To the microwell of the replication mold, PEG-DA (polyethylene glycol diacrylate, Mw=575, Sigma-Aldrich Chemicals) was added and filled. The replication mold filled with PEG-DA was left in a vacuum chamber for 5 minutes to remove air bubbles formed in the microwell. The excess PEG-DA remaining after filling the microwell was recovered by tilting the replication mold or using a capillary force using a pipette tip to be filled with PEG-DA up to the boundary of the microwell. Thereafter, a photoinitiator 2,2-diethoxyacetophenone (DEAP) was added to cover the top surface of the microwell with a solvent containing 1-5 vol%. From the time when the solvent was added, the change of the image over time was observed using an inverted microscope (TE2000, Nikon, Japan) equipped with a CCD camera (Coolsnap, Photometrics, USA). After 20 minutes of adding the solvent, 365 nm ultraviolet light was irradiated for 2 minutes using an 8 W small UV lamp (Spectronics Corp., Westbury, NY). After UV irradiation, the replica mold was dipped in IPA (isopropyl alcohol) to recover polymer microparticles. PDMS oil (Dow Corning) or Fluorinert ^® FC-40 (Sigma) was used as the solvent.

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, since the composite according to Example 3 is a hollow particle having very many pores, it was found that the specific gravity is significantly reduced compared to that of Comparative Example 1.

Evaluation example 2: Electrical conductivity and thermal conductivity

The electrical conductivity and thermal conductivity of the composite prepared according to 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 electrical conductivity and thermal diffusivity were measured based on the methods of ASTM F 390 and ASTM E 1461-92, respectively. The thermal diffusivity was converted to 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 × 10 ^-6 Thermal conductivity (W/mK) 4.0 0.5

Referring to Table 2, the electrical conductivity and thermal conductivity of the polymer-coated polymer hollow particle/epoxy composite prepared in Example 4 of the present invention are controlled by an efficient conduction effect by electrical and heat transfer passages made of copper. Therefore, it was confirmed that it exhibits remarkably excellent electrical conductivity and thermal conductivity compared to the copper/epoxy composite prepared by Comparative Example 2.

Evaluation example 3: Optical microscope

1) Examples 1, 5-6

Polymer hollow particles prepared according to Examples 1 and 5-6 were analyzed using an optical microscope. The analysis results are shown in FIGS. 2A to 2C. As an optical microscope, DM-2500 from Leica was used.

Referring to this, when the expandable particles were supplied to the microwell and heated to 90° C., unexpanded microparticles were observed as shown in FIG. 2A. And referring to Figure 2b, when feeding the expandable particles to the microwell and heating it to 100 ℃, microparticles having a round edge was observed.

When feeding expandable particles to the microwell and heating it to 110° C., a microbomb with a sharp edge was observed. And when supplying expandable particles to the microwell and heating it to 120°C, it was possible to observe the structure in which the micro bomb was ruptured. From this, it was found that the shape of the polymer hollow particle can be controlled according to the heat treatment temperature of the expandable particle.

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

2) Example 8-14

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

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

Referring to this, when the polymer hollow particles of Example 7-13 are changed to a nano pattern of a microwell of a mold and a nanopattern of a cover into a line pattern, it is possible to form a line pattern on its surface, thereby enabling nanopattern imprinting. 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 as 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 particle of Example 14 can form a hole pattern on its surface by changing the nano-pattern of the microwell of the mold and the nano-pattern of the cover into a hole pattern, thereby enabling nano-pattern imprinting. there was.

Evaluation example 4: Observing limited expansion behavior

When prepared according to Example 1, a real-time tracking process was confirmed to examine the limited expansion behavior.

Referring to this, it was found that the shape of the polymer hollow particles finally obtained is determined according to the shape of the microwell of the mold, and the expansion rate of each particle increases with time.

Evaluation example 5: particle size distribution characteristics

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 prepared according to Example 1-2 exhibited monodisperse particles having the same particle size. On the other hand, the polymer particles prepared according to Comparative Example 3 exhibited a polydispersed particle shape having different particle sizes, unlike the polymer hollow particles of Example 1-2.

In addition, the size distribution characteristics of the polymer hollow particles prepared according to Examples 15-18 were evaluated. As a result, the polymer hollow particles prepared according to Examples 15-18 exhibited monodisperse particles having the same particle size as the polymer hollow particles prepared according to Examples 1-2.

Although one embodiment has been described through the above, it is not limited thereto, and it is possible to carry out various modifications within the scope of the claims and detailed description of the invention and the accompanying drawings. Do.

10: substrate on which an intaglio pattern was formed 11: microwell
12: expandable particles 13: polymer hollow particles

Claims (17)

A first step of providing at least one expandable particle containing an expandable core comprising a blowing agent and a thermoplastic polymer shell to a substrate having an intaglio pattern;
A second step of removing excess expandable particles from the result of the first step;
A third step of expanding the expandable particles of the engraved pattern by heat-treating the result of the second step; And
Method of manufacturing a polymer hollow particle comprising a fourth step of separating the polymer hollow particles having been expanded according to the third step from the substrate. According to claim 1,
The expandable particles provided in the engraved pattern in the first step are provided as monodispersed or polydispersed particles, and the polymer hollow particles obtained according to the fourth step are prepared as polymer hollow particles that are monodispersed polymer hollow particles. Way. According to claim 1,
The first step,
One or more expandable particles comprising the expandable core and a thermoplastic polymer shell are mixed with a solvent to be provided on a substrate having an intaglio pattern, or
Method for producing hollow polymer particles, which dryly provide one or more expandable particles comprising an expandable core and a thermoplastic polymer shell. According to claim 1,
In the third step, the heat treatment is performed at 50 to 170°C. According to claim 1,
The blowing agent is a method for producing hollow polymer particles containing a low-boiling non-fluorine-based hydrocarbon compound that becomes a gas phase at a temperature below the softening point temperature of the thermoplastic resin of the thermoplastic polymer shell. 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 polymer obtained as a reaction product of a polymerizable monomer and a crosslinking agent,
The polymerizable monomer is a nitrile monomer, carboxylic acid monomer, (meth)acrylic acid ester monomer, acrylamide monomer, maleimide monomer, vinyl ether monomer, vinyl ketone monomer, aromatic divinyl monomer, N- At least one selected from the group consisting of vinyl monomers, vinyl halide monomers, and combinations thereof,
The crosslinking agent is allyl methacrylate, triacrylic formal, 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-nonanediol di(meth)acrylate, 1, 10-decanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol di(meth) 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, hydroxypibaranoic acid neopentyl glycol diacrylate, di trimethylolpropane tetraacrylate, 2 -Butyl-2-ethyl-1,3-propanediol diacrylate and a method for producing polymer hollow particles comprising any one selected from the group consisting of combinations thereof. According to claim 1,
The thermoplastic resin of the thermoplastic polymer resin shell of the expandable particles is a (meth)acrylic first repeating unit, a nitrile-based second repeating unit, and the (meth)acrylic first repeating unit and a nitrile-based second repeating unit that are not reactive. Terpolymer containing 3 repeat units,
The content of the (meth)acrylic first repeating unit is 10 to 50% by weight based on the total content of the repeating units, and the content of the nitrile second repeating unit is the first repeating unit, the second repeating unit, and the third repeating unit. 30 to 80% by weight based on the total content, the content of the third repeating unit 10 to 50% by weight of the method for producing hollow polymer particles. According to claim 1,
The blowing agent in the expandable particles is propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, normal pentane, normal hexane, isohexane, heptane, octane, petroleum ether, methane halide, tetraalkylsilane, azo Method for producing hollow polymer particles comprising any one selected from the group consisting of dicarbonamide and combinations thereof. According to claim 1,
A method of manufacturing polymer hollow particles in which line or hole patterns are formed on a substrate having the intaglio pattern to form line or hole patterns on at least one surface of the polymer hollow particles. 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 , and the method for producing the polymer hollow particles as monodispersed particles. Claims 1 to 10 is a monodispersed type particle manufactured according to the method of any one of claims 1 to 10, comprising an expandable core and a thermoplastic polymer shell, and having a specific gravity of 0.001 to 1 g/cm ³ . The method of claim 11,
The dispersion degree of the hollow polymer particles is 5% or less polymer hollow particles. Claims 1 to 10 of the monodispersed-type particles are prepared according to any one of the manufacturing method, including an expandable core and a thermoplastic polymer shell, specific gravity of 0.001 to 1g / cm ³ polymer hollow particles; And
A composite comprising at least one material selected from an electron conductive material, a material having electromagnetic wave shielding performance, a thermal electron conductive material, and a polymer resin. The method of claim 13,
The composite is a polymer hollow particle; And a structure containing a coating film containing at least one material selected from among the electroconductive material disposed on the surface of the polymer hollow particle, a material having electromagnetic wave shielding performance, a thermoelectroconductive material, and a polymer resin, or
The composite is a composite having a structure in which one or more materials selected from polymer hollow particles, an electron conductive material, a material having electromagnetic wave shielding performance, a thermal electron conductive material, and a polymer resin are complexed. The method of claim 13,
The dispersion degree of the hollow polymer particles is 5% or less. The method of claim 1, wherein the expanded polymer particles are single particles or one-body particles. The method of claim 1, further comprising subjecting the polymer hollow particles to a surface treatment with a fluorine-based material, wherein the fluorine-based material is 1,1-difluoroethane.

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