KR100876211B1 - Expandable polystyrene bead including plate-shaped talc coated by resin and production method thereof - Google Patents

Abstract

A foaming polystyrene bead, a method for preparing the polystyrene bead, and a polystyrene foam prepared by foaming the polystyrene bead are provided to lower heat conduction. A method for preparing a foaming polystyrene bead comprises the steps of mixing plate talc with a resin selected from the group consisting of a polypropylene wax, a polyethylene wax or a low molecular weight polystyrene having a weight average molecular weight of 500-1,000 with a high speed to coat the plate talc with the resin; and adding the coated plate talc to polymerize a polystyrene bead having a diameter of 0.3-3 mm, wherein the content of the plate talc is 0.1-10 parts by weight to the foaming polystyrene bead.

Description

Expandable polystyrene beads including plate-shaped TALC coated by resin and production method

The present invention relates to expandable polystyrene beads. In particular, the present invention relates to expandable polystyrene beads comprising a plate-shaped talc coated with a resin, and a method for producing the same.

Polystyrene resin, which is a thermoplastic resin, is widely used in various industrial fields such as daily necessities, electrical and electronic products, packaging materials, and building materials because of excellent molding processability.

In particular, polystyrene foams produced by foaming polystyrene resins are widely used as heat insulating materials. Polystyrene foam is generally obtained by foaming polystyrene beads impregnated with a blowing agent.

  In general, the heat insulating material must have low thermal conductivity in order to have high heat insulating properties.

 Conventionally, fluorine-based gas is used as a blowing agent in polystyrene resin foams to satisfy the requirements of such insulation, but such fluorine-based gas is the main culprit of destroying the ozone layer, and the insulation of the insulation gradually decreases due to separation from the foam with time. There is a problem that is not currently recommended.

In addition, it is desirable that the thickness of the heat insulating material used for increasing the interior area of the building is thin. However, when the thickness of the heat insulating material becomes thin, there is a problem that the heat insulating performance is sharply reduced.

Therefore, it is necessary to produce expandable polystyrene beads which produce a foam having high heat insulation even at a thin thickness without using a fluorine-based gas.

Recently, in accordance with such a demand, a method for producing an expandable polystyrene polymer containing graphite particles has been introduced in Korea Patent Publication No. 2001-0012557.

However, in the case of using the method of increasing the thermal insulation by adding graphite particles or the like in this way, the additives added to the expandable polystyrene polymer may make the adhesion between the pre-foamed particles difficult, thereby producing a low quality foam. In addition, such graphite particles increase or break the cell structure of the foam, causing micropores, and as a result, the moisture permeability is increased. Furthermore, when the heat insulating material formed of such graphite particles is loaded or installed outside to directly expose sunlight, the heat insulating material may act as a black body absorbing sunlight to raise the temperature of the heat insulating material. This rise in temperature can in this case melt the expandable polystyrene polymer inside the insulation. In addition, the additives also do not distribute uniformly on the foam, there is a problem that it is difficult to ensure uniform heat insulation.

In addition, a method for producing a molded article of a particulate thermal insulation increasing material (hereinafter also referred to as an 'opaque material'), in particular a polystyrene foam containing carbon black, graphite and aluminum particles, has been introduced in European Patent Publication No. 620246.

On the other hand, the method of containing the particulate athermanous material in the molding includes a method of coating the surface of the prefoamed polystyrene beads with the athermanous material and embedding the athermanous material in the polystyrene beads which have not yet been foamed. Methods are known.

According to these methods, however, it is difficult to evenly distribute the athermanous material in the foam, which greatly impairs the adhesion of the prefoamed foam granules, resulting in a low quality foam, and the formation of the athermanous material at the surface of the molding. It can also cause the particles to peel off.

In order to solve the problems of the prior art as described above, the present invention is a novel opaque material which is distinguished from the conventional opaque material, in order to produce a polystyrene-based resin foam having a low thermal conductivity, a plate-shaped talc coated with resin It is intended to provide a coated polystyrene beads and a method of manufacturing the same.

In addition, the present invention is a novel opaque material, which is distinguished from conventional opaque materials, to prepare polystyrene-based resin foams having low thermal conductivity, and is prepared by adding a plate-shaped talc coated with resin to the polymerization process of styrene. To provide a bead and a method of making the same.

The present invention also provides a polystyrene foam made of polystyrene beads containing plate-shaped talc coated with resin.

In order to solve the above problems, the present invention includes the plate-shaped talc in the polystyrene beads, it is possible to reflect the incident infrared rays to the plate-shaped talc, it is possible to obtain a low thermal conductivity, that is, excellent thermal insulation.

In addition, the present invention by coating the plate-shaped talc with a resin, the plate-shaped talc can be uniformly distributed on the outer surface or the inside of the polystyrene beads.

Therefore, the present invention can sufficiently reflect the incident infrared rays through the plate-shaped talc uniformly distributed in the polystyrene beads, thereby obtaining low thermal conductivity, that is, high thermal insulation.

Thus, the expandable polystyrene beads according to one aspect of the present invention is a plate-shaped talc coated with a resin is coated on the outside of the beads, characterized in that the diameter of 0.3 to 3mm.

In addition, the expandable polystyrene beads according to another feature of the present invention is characterized in that the plate-shaped talc coated with a resin is distributed in the beads, the diameter is 0.3 to 3mm.

In addition, the method for producing expandable polystyrene beads according to another aspect of the present invention comprises the step of coating the plate-like talc with the resin by high-speed mixing; And coating polystyrene beads having a diameter of 0.3 to 3 mm with the coated plate-shaped talc; To include, the content of the plate-like talc is characterized in that 0.1 to 10 parts by weight based on 100 parts by weight of the expandable polystyrene beads.

In addition, the method for producing expandable polystyrene beads according to another aspect of the present invention comprises the step of coating the plate-like talc with the resin by high-speed mixing; And adding the coated plate-like talc to polymerize polystyrene beads having a diameter of 0.3 to 3 mm. To include, the content of the plate-like talc is characterized in that 0.1 to 10 parts by weight based on 100 parts by weight of the expandable polystyrene beads.

In addition, the polystyrene foam according to another feature of the present invention is characterized in that it is prepared by foaming the pre-foamed polystyrene beads.

The plate-shaped talc used in the present invention can reflect the incident infrared rays to improve the thermal insulation performance, the content of which is preferably 0.1 to 10 parts by weight based on 100 parts by weight of polystyrene beads.

Since the plate-like talc is not a black body such as graphite particles, it is a reflector, so even when loaded or installed outside, there is no problem of absorbing the incident sunlight and increasing the temperature, and there is no peeling phenomenon.

At this time, when the content of the plate-like talc is higher than 10 parts by weight with respect to 100 parts by weight of polystyrene beads, the amount of the plate-like talc is too high to penetrate into the polystyrene bead particles, thereby inhibiting the dispersion stability of the plate-like talc. . On the other hand, when the content of the plate-like talc is lower than 0.1 parts by weight relative to the polystyrene beads, the dispersion stability of the plate-shaped talc is maintained, but the content is insufficient to reflect the incident infrared rays sufficiently to achieve the desired thermal insulation.

The general form of talc is mainly in the form of a powder, so that the space between the particles and the particles does not reflect the incident infrared rays in a specific direction, and because the incident infrared rays are rotated or refracted and diffusely reflected in various directions, even though they are contained in polystyrene beads However, it is difficult to have a significant influence on the thermal insulation of polystyrene beads.

In addition, it is not easy to coat the polystyrene beads with such a talc in the form of powder, and even if introduced into the polymerization process, there is a problem that does not penetrate well into the polystyrene beads.

On the contrary, the plate-shaped talc used in the present invention has a plate-like structure having a length ratio (particle diameter / cross-sectional thickness) to the thickness of the particles, so that it is possible to effectively reflect the incident infrared rays in one direction. Thus, it is possible to lower the thermal conductivity, thereby obtaining a high thermal insulation. Such plate-shaped talc of the present invention has a layered structure (LAMELLA) or a plate-like structure, all of which are referred to as plate-shaped talc.

As the plate-shaped talc used in the present invention, one having an average particle diameter of 5 to 50 µm, preferably 8 to 15 µm, is used. If the particle diameter of the plate-shaped talc is too small, it is difficult to sufficiently reflect the incident infrared rays, and if the particle size of the plate-shaped talc is too large, it may be bent, so that the effect of reflecting infrared rays is rather deteriorated.

However, such plate-shaped talc itself is not easily coated on the surface of the polystyrene beads, or there is a problem that does not penetrate into the polystyrene beads.

Therefore, in the present invention, by coating the surface of the plate-like talc with a resin and the like, the resin-coated plate-like talc can be easily impregnated or closely distributed in the prepared heat insulating material, which is always excellent in any form or cutting Insulation performance can be exhibited.

Specifically, when the plate-like talc is coated with the resin, the resin increases the adhesion or distribution of the plate-shaped talc with the polystyrene beads, so that the plate-shaped talc can adhere well to the surface of the polystyrene beads, and the plate-shaped talc is polystyrene beads. Allows even penetration into the interior. Accordingly, it is possible to increase the content of the plate-shaped talc attached or included in the polystyrene beads.

In addition, the plate-like talc may be coated with a resin, thereby preventing generation of heat loss paths due to contact between the plate-shaped talc and the particles.

In addition, the plate-like talc can be coated with a resin, thereby preventing damage to the polystyrene bead surface and preventing deterioration in foaming quality.

Such a method for preparing polystyrene beads containing plate-shaped talc coated with the resin of the present invention can be broadly classified into a coating method and a polymerization method.

First, look at the coating method,

Mixing plate-like talc with resin at high speed to produce a plate-shaped talc coated with resin; And

It comprises a step of producing by adding 0.1 to 10 parts by weight of the resin-coated plate-shaped talc with respect to the polystyrene beads in the coating process of polystyrene beads.

The method of coating the plate-like talc on the polystyrene beads consists of mixing the polystyrene beads and the plate-shaped talc at a high speed through a super mixer or a screw conmixer.

The talc used preferably has a plate-like structure. The plate-shaped talc is not limited in shape, and may be a polygon or a circle such as a triangle or a rectangle.

The average particle size of the plate-shaped talc is preferably 5 to 50 µm, preferably 8 to 15 µm.

As for the length ratio (particle diameter / cross-sectional thickness) (Aspect ratio) with respect to the thickness of plate-shaped talc, 100-1000 are preferable. If the numerical value is less than 100, the plate is small and does not sufficiently reflect incident infrared rays. If the value is more than 1000, the plate is large, but may be curved, but the effect of reflecting infrared rays is inferior.

Here, the resin used to coat the plate-shaped talc is not particularly limited as long as it can be adsorbed on the plate-like talc to lower the thermal conductivity of the plate-shaped talc, and may be polypropylene wax, polyethylene wax or a low molecular weight having a weight average molecular weight of 500 to 1,000. Polystyrene is preferably used.

Here, the polystyrene beads are composed only of polystyrene, or in combination with polystyrene, ethylenically unsaturated comonomers, especially alkyl styrene, divinyl benzene, acrylonitrile or α-methyl styrene, in an amount of 20 parts by weight with respect to 100 parts by weight of polystyrene beads It may be a copolymer further comprising.

The polystyrene beads of the present invention may be prepared by a styrene suspension polymerization method, but are not limited thereto.

The size of the polystyrene beads of the present invention is 0.3 to 3mm in diameter, preferably 0.35 to 2mm.

In addition, the content of the plate-like talc coated on the polystyrene beads is preferably 0.1 to 10 parts by weight based on the polystyrene beads.

On the other hand, the polystyrene bead may include 0.5 to 2 parts by weight, preferably 0.5 to 1 part by weight of graphite, carbon, aluminum, zinc, etc. in order to enhance the effect of heat insulation and flame retardancy.

Such polystyrene beads can also be further coated with conventional coatings. Such further coatings can be, for example, metal stearates, glyceryl esters or finely divided silicates.

On the other hand, when looking at the polymerization method,

Mixing plate-like talc with resin at high speed to produce a plate-shaped talc coated with resin; And

And adding a plate-like talc coated with the resin to the polymerization process of the polystyrene beads.

Here, since the production of the plate-shaped talc coated with the resin is the same as the coating method, the description of the specific method will be omitted.

With the resin coating of the plate-shaped talc, the amount of the plate-shaped talc added in the coating and polymerization process of the polystyrene beads is drastically increased. In addition, the plate-like talc used in the present invention can be maximized when using the thinner and wider plate-like particles.

In addition, since the polystyrene beads used are similar to those in the coating method, except that the plate-like talc is added during the polymerization process, description of the specific characteristics thereof will be omitted.

Specifically, in the polymerization process of the polystyrene beads, 0.1 to 10 parts by weight of the plate-shaped talc is preferable with respect to 100 parts by weight of the polystyrene beads as the amount of the plate-shaped talc coated with the resin.

In addition, in order to enhance the effect of heat insulation and flame retardancy, 0.5 to 2 parts by weight, preferably 0.5 to 1 part by weight, based on 100 parts by weight of polystyrene beads, of heat insulation enhancement additives such as graphite, carbon, aluminum, and zinc at a polymerization conversion rate of 70% or more. It can be added to the polymerization. This results in the thermal insulation additives being located outside the polystyrene beads, thus preventing infrared light from diffusing or refracting through the space between the plate-shaped talc and the particles in the polystyrene beads and preventing diffraction or refraction. Can be obtained additionally.

On the other hand, the above-described polymerization process of the present invention may be prepared through a conventional polymerization process of styrene, but is not limited thereto.

Suspension stabilizers may additionally be used in this styrene suspension polymerization process. As suspension stabilizers, inorganic pickling dispersants such as magnesium pyrophosphate or calcium phosphate, or organic dispersants such as polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), or polycellulose-based dispersants are advantageously used.

When the plate-like talc is included in the polystyrene beads through the polymerization method as described above, since the plate-shaped talc is contained in the polystyrene beads, the polystyrene beads are stably maintained over time, and thus excellent aging stability can be expected. In addition, the talc is uniformly distributed in the polystyrene beads and does not fall off from the polystyrene beads in the processing step, thereby ensuring uniform heat insulating properties.

In addition, the fusion between the polystyrene beads is easy, it can be expected that the production of the polystyrene foam is more easily performed. Specifically, the talc is distributed inside the polystyrene beads so that the adhesion of the prefoamed beads does not cause a problem.

On the other hand, in the polystyrene bead polymerization step, preferably 3 to 10 parts by weight of a blowing agent may be further added to 100 parts by weight of the polystyrene beads. The blowing agent may be added to the suspension before, during or after the polymerization. As the blowing agent, aliphatic hydrocarbons having 4 to 6 carbon atoms are preferably used. Examples thereof include isobutane, n-butane, isopentane, n-pentane and the like.

The polystyrene beads of the present invention may further comprise conventional auxiliaries, such as peroxide initiators, chain transfer agents, foaming aids, nucleating agents and plasticizers, together with the blowing agent.

In addition, the polystyrene beads of the present invention may further include a flame retardant or a flame retardant synergist for the flame retardancy of the heat insulating material, such a flame retardant is 0.6 to 6 parts by weight based on 100 parts by weight of polystyrene beads, 0.1 to 1 flame retardant It is included in parts by weight.

As flame retardants, aliphatic, cycloaliphatic and aromatic bromine compounds such as hexabromocyclododecane, pentabromomonochlorocyclo hexane, pentabromophenyl allyl ether, and the like are preferably used. As flame retardants, unstable organic compounds containing C-C- or O-O- functional groups, for example bicumyl and dicumyl peroxide, are preferably used.

After the polystyrene bead polymerization process, preferably, the step of coating the polystyrene beads with metal stearate, glyceryl ester or fine silicate, which is a conventional coating agent, may be further performed.

In addition, pre-foaming the polystyrene beads may be further performed.

The polystyrene beads in which the plate-shaped talc thus formed is added to the coating and polymerization process may be foamed to form a polystyrene foam.

As the foaming method of the polystyrene beads, a conventional foaming method can be used. If the foaming rate is too high, the thermal conductivity is high, if the foaming rate is too low, too much polystyrene may be an economic problem. The polystyrene foam thus formed has a plurality of foam spaces in which plate-shaped talc can be located.

Thus, the plate-shaped talc contained in the foam reflects or absorbs the incident infrared rays, thereby significantly lowering the thermal conductivity. In particular, the plate-shaped talc in the present invention is composed of a plate-like, the infrared reflectivity is significantly increased.

On the other hand, the method for producing a polystyrene foam using the polystyrene beads of the present invention may be prepared by pre-foaming the polystyrene beads prepared, and then foaming the pre-foamed polystyrene beads.

According to the polystyrene beads of the present invention, as described above, low thermal conductivity, that is, excellent heat insulating property can be obtained by reflecting or absorbing infrared rays into which plate-shaped talc penetrated into the polystyrene beads is incident.

In addition, the resin coated on the plate-shaped talc does not inhibit the adhesion between the polystyrene foam foam granules, and the plate-shaped talc allows to achieve excellent flame retardancy.

The expandable polystyrene beads including the plate-shaped talc of the present invention prepared through the polymerization process have the advantage that time stability is maintained even over time. In addition, the talc is uniformly distributed in the polystyrene beads and is not separated from the polystyrene beads even in the processing process, thereby ensuring uniform thermal insulation.

Hereinafter, the present invention will be described in detail by way of examples. The following examples are merely illustrative of the present invention, and the protection scope of the present invention is not limited to the following examples.

Example 1

A: coated with resin Plate  Talc manufacturers

The talc in the form of ore is put into a ball mill for about 20 hours under compressed air and steam By milling, 15 kg of plate-shaped talc were selected which had an average particle diameter of 8 to 15 mu m and a length ratio (particle diameter / section thickness) (Aspect ratio) to the thickness of the talc.

The plate-like talc thus obtained was added to a supermixer KAWATA SMV 20 with 5 kg of polyethylene wax as a resin and mixed at high speed at 600 RPM to obtain a plate-shaped talc coated with resin.

B: by polymerization method Plate  Talc Polystyrene Bead  Internal input

38 kg of pure water was added to the 0.1 m ³ reactor as a dispersion medium, and 137 g of tricalcium phosphate as a first stabilizer was suspended, and 36 kg of styrene was introduced thereto to start polymerization.

105 g of benzoyl peroxide as an initiator and 240 g of hexabromo cyclododecane as a flame retardant were added while heating up at 88 degreeC, and superposition | polymerization was continued.

 Thereafter, 370 g of the resin-coated plate-shaped talc previously obtained with respect to 1 kg of styrene was dissolved for 30 minutes, and then charged into the reactor 1 hour after the start of polymerization.

Thereafter, 39 g of the second stabilizer polyvinyl alcohol was previously dissolved in 390 g of pure water, and then charged into the reactor 3 hours after the start of polymerization.

2.95 kg of n-pentane as a blowing agent was introduced into the reactor 6 hours after the start of polymerization, and maintained at 123 ° C. for 2 hours and a half to remove unreacted styrene monomer, followed by cooling. Draining, dehydration and drying yielded the desired expandable polystyrene beads in which the plate-shaped talc coated with resin was contained within the beads.

C: polystyrene Foam  Produce

The foamed polystyrene beads thus obtained were introduced into a 1000L Sunghoon machine prefoam, and steam was applied at 0.32 kg / cm 2 for 28 seconds to prefoam so that the specific gravity was 15.6 g / l.

After 4 hours, the pre-expanded expanded polystyrene beads were placed in a Kurtz pad molding machine, primary steam was applied for 5 seconds at 0.6 kg / cm 2, and secondary steam was applied for 5 seconds at 0.75 kg / cm 2 to produce the desired product. It was.

Example 2

D: by coating method Plate  Talc Polystyrene Bead  coating

70 kg of expanded polystyrene beads (F351, Dongbu HiTek Co., Ltd.) and 70 g of the resin-coated plate-shaped talc prepared in Example 1 were added to a KAWATA 20L SUPER MIXER, and rotated at high speed at 600 rpm for 7 minutes to form the expanded polystyrene beads into plate-shaped talc particles. Coated with.

E: polystyrene Foam  Produce

The coated foamed polystyrene beads were introduced into a 1000L Sunghoon machine prefoam and steamed at 0.32 kg / cm 2 for 33 seconds to prefoam to have a specific gravity of 14.7 g / l. After 4 hours, the pre-expanded foamed polystyrene particles were placed in a Kurtz pad molding machine, primary steam was applied for 5 seconds at 0.6 kg / cm 2, and secondary steam was applied for 5 seconds at 0.75 kg / cm 2 to obtain the desired product. Produced.

Comparative Example 1

  Expandable polystyrene beads (Dongbu Hitech Co., Ltd.) were put into a 1000L Sunghoon machine prefoam and steam was applied at 0.32 kg / cm 2 for 28 seconds to pre-foam so that the specific gravity was 14.8 g / l.

After 4 hours, the pre-expanded expanded polystyrene beads were placed in a Kurtz pad molding machine, primary steam was applied for 5 seconds at 0.6 kg / cm 2, and secondary steam was applied for 5 seconds at 0.75 kg / cm 2 to produce the desired product. It was.

Comparative Example 2

Plate-like talc was obtained as in Example 1 except for coating with resin.

370 g of the plate-like talc thus obtained were used in the same manner as in Example 1 to prepare expandable polystyrene beads.

The foamed polystyrene beads thus prepared were put into a 1000L Sunghoon machine prefoam and steam was applied at 0.32 kg / cm 2 for 29 seconds to pre-foam so that the specific gravity was 16.1 g / l.

After 4 hours, the pre-expanded expanded polystyrene beads were placed in a Kurtz pad molding machine, primary steam was applied for 5 seconds at 0.6 kg / cm 2, and secondary steam was applied for 5 seconds at 0.75 kg / cm 2 to produce the desired product. It was.

Comparative Example 3

Ore type talc is added to a ball mill for about 20 hours under compressed air and steam. By milling, 15 kg of powdery talc with an average particle diameter of 8 to 15 µm and a powder shape was selected.

The powdery talc thus obtained was added to the supermixer KAWATA SMV 20 with 5kg of polyethylene wax as a resin and mixed at high speed at 600 RPM to obtain a powdery talc coated with resin.

370 g of the powdered talc thus obtained was used in the same manner as in Example 1 to prepare expandable polystyrene beads.

The obtained expandable polystyrene beads were introduced into a 1000L Sunghoon machine prefoam and steam was applied at 0.32 kg / cm 2 for 26 seconds to pre-foam so that the specific gravity was 15.4 g / l.

After 4 hours, the pre-expanded expanded polystyrene beads were placed in a Kurtz pad molding machine, primary steam was applied for 5 seconds at 0.6 kg / cm 2, and secondary steam was applied for 5 seconds at 0.75 kg / cm 2 to produce the desired product. It was.

Comparative Example 4

The talc in the form of ore was put into a ball mill, and milled for about 20 hours under compressed air and steam to select a powdery talc having an average particle diameter of 8 to 15 µm and a powder form.

Expanded polystyrene beads were prepared in the same manner as in Example 1 except that 370 g of the obtained powdery talc was used for the polymerization reaction.

The obtained expandable polystyrene beads were introduced into a 1000L Sunghoon machine prefoam and steam was applied at 0.32 kg / cm 2 for 32 seconds to prefoam to a specific gravity of 14.1 g / l.

After 4 hours, the pre-expanded expanded polystyrene beads were placed in a Kurtz pad molding machine, primary steam was applied for 5 seconds at 0.6 kg / cm 2, and secondary steam was applied for 5 seconds at 0.75 kg / cm 2 to produce the desired product. It was.

Experimental Example

The polystyrene foam products prepared in Examples 1 and 2 and Comparative Examples 1 to 4 were dried at 60 ° C. for 24 hours, and then hot-cut to 200 × 200 × 50 mm to prepare sample specimens for thermal conductivity measurement.

The prepared specimen was allowed to stand for 48 hours in a 60 ° C. drying chamber and taken out. The thermal conductivity of the sample specimen was measured by a Anacon TCA8 thermal conductivity analyzer, and the results are shown in Table 1.

After 48 hours Specific gravity (g / ℓ) Thermal Conductivity (w / mK) Example 1 16.6 0.0302 Example 2 15.3 0.0310 Comparative Example 1 16.6 0.0364 Comparative Example 2 17.1 0.0320 Comparative Example 3 16.0 0.0348 Comparative Example 4 15.8 0.0360

As can be seen from Table 1, polystyrene foam prepared by incorporating the plate-shaped talc represented by Example 1 of the present invention into a polymerization process, and Example 2, than the conventional polystyrene foam product (Comparative Example 1) represented by Comparative Example 1. Polystyrene foam prepared by coating a plate-shaped talc represented by polystyrene beads showed a significantly low thermal conductivity.

Remarkably lower polystyrene foam prepared by injecting the plate-shaped talc coated with the resin represented by Example 1 into the polymerization process than the polystyrene foam produced using the plate-shaped talc not coated with the resin represented by Comparative Example 2 Thermal conductivity is shown.

In addition, the polystyrene foam prepared by injecting the plate-shaped talc represented by Example 1 of the present invention into the polymerization process showed a significantly lower thermal conductivity than the polystyrene foam prepared using the powdered talc represented by Comparative Example 3.

And, as shown in Comparative Example 4, the polystyrene foam, which is not coated with resin and manufactured using a non-plate-shaped powder talc, has a lower thermal conductivity than the conventional polystyrene foam of Comparative Example 1, It showed higher thermal conductivity than Comparative Examples 2 and 3.

From these experimental examples, it can be seen that the case of using a plate-shaped talc coated with resin exhibits the lowest thermal conductivity.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the technical idea of the present invention, and it is obvious that the present invention belongs to the appended claims. Do.

Polystyrene foam produced through the polystyrene bead prepared through the method for producing a polystyrene bead of the present invention has a low thermal conductivity and excellent stability over time can be widely used as a heat insulating material for building materials.

Claims (20)

delete Resin-coated plate-shaped talc is distributed inside the beads, 0.3-3mm in diameter, The resin is selected from the group consisting of polypropylene wax, polyethylene wax or low molecular weight polystyrene having a weight average molecular weight of 500 to 1000, Expandable polystyrene beads, characterized in that the content of the plate-like talc is 0.1 to 10 parts by weight based on 100 parts by weight of the beads. delete delete The method of claim 2, The expandable polystyrene beads having an average diameter of the plate-shaped talc is 5 to 50 μm. The method of claim 2, The expandable polystyrene beads having a length ratio (particle diameter / cross-sectional thickness) to the thickness of the plate-shaped talc is 100 to 1000. delete Coating the plate-like talc with a resin selected from the group consisting of polypropylene wax, polyethylene wax or a low molecular weight polystyrene having a weight average molecular weight of 500 to 1000; And Adding the coated plate-like talc to polymerize polystyrene beads having a diameter of 0.3 to 3 mm; Including but not limited to: Method for producing a polystyrene bead characterized in that the content of the plate-like talc is 0.1 to 10 parts by weight relative to the expandable polystyrene beads. delete The method of claim 8, A method for producing the expandable polystyrene beads, which is prepared by additionally mixing 0.5 to 2 parts by weight of an athermanous material selected from graphite, carbon, aluminum, or zinc together with the plate-like talc. delete The method of claim 8, A method for producing the expandable polystyrene beads having an average diameter of the plate-shaped talc is 5 to 50 ㎛. The method of claim 8, The length ratio (particle diameter / cross-sectional thickness) with respect to the thickness of the said plate-shaped talc is the manufacturing method of the said expanded polystyrene bead. The method of claim 8, A method for producing the expandable polystyrene beads further comprising the step of pre-expanding the expandable polystyrene beads. The method of claim 8, A method for producing the expandable polystyrene beads, wherein the mixing of the plate-shaped aluminum particles and the resin is performed with a super mixer or screw mixer. The method of claim 8, In the polymerization step, 3 to 10 parts by weight of the blowing agent is further added based on 100 parts by weight of the polystyrene beads.  The method of claim 8, In the polymerization step, 0.6 to 6 parts by weight of flame retardant and 0.1 to 1 parts by weight of flame retardant is added to 100 parts by weight of the polystyrene beads, the method for producing the expandable polystyrene beads. The method of claim 8, In the polymerization step, further adding any one or more suspension stabilizers selected from the group consisting of magnesium pyrophosphate, calcium phosphate, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA) and polycellulose-based dispersant Method for producing the expandable polystyrene beads, characterized in that. The method of claim 8, Coating the polymerized polystyrene beads with a metal stearate, glyceryl ester or finely divided silicate. A polystyrene foam prepared by foaming the prefoamed polystyrene beads of claim 14.