KR101484615B1 - Method for manufacturing styrene-form with excellent insulation and non-deformation - Google Patents

Abstract

The present invention relates to a method for producing an extruded styrene foam which is excellent in heat insulation and does not cause deformation when exposed to the outside, and is characterized in that graphite powder, titanium oxide, a flame retardant and a nucleating agent are added to a polystyrene resin in an extruder, The extruded styrene foam is excellent in heat insulation property and does not cause deformation during outdoor exposure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing an extruded styrene foam,

The present invention relates to a method for producing an extruded styrene foam which is excellent in heat insulation property and does not cause deformation during outdoor exposure. More specifically, the present invention relates to a method for producing an extruded styrene foam which is excellent in heat insulation by using titanium oxide together with graphite in a main raw material, To a method for producing an extruded styrene foam.

Generally, the density of foamed polystyrene foam boards used for thermal insulation is about 30 g / l because the thermal conductivity of the expanded polystyrene foam has a minimum value at that density.

To save material and space, it is desirable to use foam boards with lower density, especially less than 15 g / l, for insulation, and the production of such foams is not technically problematic.

However, the low density foam board drastically reduces the insulation performance and does not meet the requirements of the thermal conductivity grade 035 (DIN 18 164, part 1).

It is known that the thermal conductivity of the foam can be reduced by the incorporation of heat-resistant materials such as carbon black, metal oxides, metal powders or pigments.

Thus, EP-A 372 343 describes polystyrene foams containing from 1 to 25% by weight of carbon black, in which case the particle size of the carbon black is between 10 and 100 nm. The polystyrene foam described in the above document is produced mainly by extrusion, and preferably has a density of 32 to 40 g / l. Also disclosed is a method for producing fine-particle polystyrene containing a foaming agent by mixing a carbon black concentrate in polystyrene with a foaming agent with a polystyrene melt, and extruding and crystallizing the mixture to produce fine-particle polystyrene containing a foaming agent.

International Patent Publication No. 94/13721 describes a similar foam having a particle size of carbon black of more than 150 nm.

EP-A-620 246 describes an expanded polystyrene foam molding comprising particulate heat-resistant materials, especially carbon black and also graphite, wherein the density of the molding is less than 20 g / l.

The incorporation of the particles into the molding is preferably carried out by coating the surface of the prefoamed polystyrene beads or by embedding them in the polystyrene sieve which has not yet been foamed. However, distributing the particles on the surface of the polystyrene particles greatly impairs adhesion of the prefoamed beads, resulting in low-quality foams, and the particles can also be peeled from the surface of the molding. In both cases, the particles are not uniformly distributed within the polystyrene particles.

Although the molded article having the above-mentioned non-heat-absorbing particles reduces the thermal conductivity, when the resin is exposed to the outdoors, the color is black and the infrared ray is easily absorbed, causing a problem of shrinkage, expansion and / or warping depending on the temperature difference between the upper and lower parts of the molded article . That is, according to FIG. 1, the color of the non-heat-treated particles, that is, the color of the molded article in which the graphite is not mixed with the graphite, and the surface temperature thereof are measured. The molded article containing the graphite has a black color, , Which may cause warpage in long-term outdoor exposure.

Accordingly, the present inventors have studied a method for reducing deformation according to the temperature of outdoor moldings of existing moldings and, when titanium oxide is added together with graphite, reflect infrared rays and ultraviolet rays during outdoor exposure to reduce the temperature rise of the foam, Styrene foam is not deformed and the present invention has been completed.

Accordingly, a problem to be solved by the present invention is to provide a method for producing an extruded styrene foam which is excellent in heat insulation and does not cause deformation during outdoor exposure.

In order to solve the above problems,

0.1 to 5% by weight of graphite powder and 0.1 to 1% by weight of titanium oxide, 1 to 5% by weight of bromine-based bromocyclo dodecane (HBCD) and 0.3 to 4% by weight of a nucleating agent are mixed in a polystyrene resin with respect to the weight of the resin, Melting; And

And 3 to 15% by weight of a blowing agent based on the weight of the resin is injected into the melt to extrude the extruded styrene foam. The extruded styrene foam is excellent in heat insulation and does not deform during outdoor exposure.

In the process for producing an extruded styrene foam according to the present invention, the titanium oxide is preferably a white powder having a density of 0.4 to 1.2 g / m, and the graphite preferably has a density of 20 to 40 g / l.

In addition, the graphite powder may be one of natural graphite or synthetic graphite (artificial graphite), while physical properties of the foam may be reduced while thermal conductivity is lowered. The flame retardant HBCD (Hexa bromocyclo dodecane) may be expanded polystyrene foam XPS (extruded polystyrene foam), and the nucleating agent is selected from the group consisting of TALC, calcium carbonate and silica, and the blowing agent is selected from the group consisting of H ₂ O, alcohol, HCFCs HCFC-22, HCFC-142b), butane, CO2, and DME (CH3COCH3).

The production method according to the present invention as described above can produce an extruded polystyrene foam having low density and low thermal conductivity, good processing characteristics and good physical properties, and at the same time having excellent heat insulation property without causing deformation during outdoor exposure.

Fig. 1 is a photograph showing the hue of the molded article in which graphite is not mixed with graphite and the surface temperature thereof.
2 is a photograph showing the states of the styrene foam obtained in Example 1 and Comparative Examples 1 and 2. Fig.

Hereinafter, a method for producing an extruded styrene foam having excellent heat insulation properties according to the present invention will be described in detail with reference to preferred embodiments thereof.

The present invention relates to a polystyrene resin composition comprising 0.1 to 5% by weight of graphite powder and 0.1 to 1% by weight of titanium oxide, 1 to 5% by weight of bromine-based bromocyclo dodecane (HBCD) and 0.3 to 4% Mixing and melting the mixture; And 3 to 15% by weight of a blowing agent based on the weight of the resin to the melt, and extruding the extruded styrene foam. The extruded styrene foam is excellent in heat insulation and does not deform during outdoor exposure.

In the melting step, the main material, polystyrene resin (polymer), preferably has a weight average molecular weight of 20 to 300,000 and is used for extrusion use. The styrofoam polystyrene polymer recycled according to the extrusion conditions can be used at 0.1 to 50% of the weight of the main material. However, it is necessary to prevent the process anxiety due to the deterioration of the heat insulation due to the open cell formation or the quality unevenness.

The graphite powder, which is an additive added to improve the heat insulation property and good physical properties, can be either natural graphite or synthetic graphite (artificial graphite), which is used in a range of 0.1 to 5% by weight based on the weight of the polystyrene resin . If it is used in an amount of less than 0.1% by weight, it is not preferable to improve the heat insulating property, and if it is used in an amount exceeding 5% by weight, it is not preferable because it affects the cell structure including opening the cell and increases the thermal conductivity rather than the decrease in thermal conductivity.

The graphite used preferably has a density of 20 to 40 g / l, and when the density of graphite is less than 20 g / l, it is difficult to maintain the product shape with a low density, and it is uneconomical to increase the manufacturing cost at a high density exceeding 40 g / .

The synthetic graphite, that is, artificial graphite refers to graphite which has undergone a graphiteization process when the coke or the like extracted from petroleum coke or coal, which is remnant after petroleum refining, is heated at 2,500 ° C. or higher, Graphite (synthetic graphite).

The titanium oxide used to reduce warpage caused by outdoor exposure is white powder, which protects the foam from deformation by reflecting ultraviolet rays, infrared rays,

The titanium oxide is prepared by oxidizing gemite aluminumite and is surface-coated with a metal oxide (or hydroxide). The titanium oxide is an organic compound such as polyhydric alcohols, alkanolamines, siloxanes, The surface is treated with another material.

As the titanium oxide, there are two different crystal forms of rutile, which is a spherical structure, and anatase, which is a planar structure. Of these, rutile, which is stabilized and weak in activity and has a relatively small permeability, is preferably used Do.

The amount of titanium oxide to be used is preferably within a range of 0.1 to 1% by weight based on the weight of the polystyrene resin. When the amount is less than 0.1% by weight, the amount of titanium oxide used is small and the effect of improving warpage is not exhibited. .

It is preferable that the density of the titanium oxide used is in the range of 0.4 to 1.2 g / mℓ. When the density of the titanium oxide is less than 0.4 g / mℓ, the particle size is small and it is difficult to disperse in the foam. When the density is more than 1.2 g / Degrade and adversely affect the cells of the foam and are uneconomical.

It is preferable to use a bromine-based flame retardant because bromine enters the foamed polystyrene foam board, and self-extinguishing property is obtained by a flame retarding mechanism such as a nonflammable gas generating and extinguishing function. The flame retardant may be used in the form of a powder or in the form of a pellet mixed with a polystyrene resin before the addition (master batch). The amount of the flame retardant used is preferably in the range of 1 to 5% by weight based on the weight of the polystyrene resin, , The flammability standard of KS M 3808 can not be met, and when it exceeds 5 wt%, use of a high-flame retardant agent is not economical, and the strength and thermal conductivity of the product are lowered.

The brominated flame retardant is preferably HBCD (Hexa bromocyclo dodecane), and the HBCD (Hexa bromocyclo dodecane) is an organic halogen-based flame retardant of hexabromocyclododecane. The polystyrene-based EPS expanded polystyrene foam) or extruded polystyrene foam (XPS).

Another additive, a nucleating agent, is used to complement the heat insulation property in the production of the expandable polystyrene polymer by extrusion, and at the same time, it is used to make the size of the foamed cell small or uniform. Its usage is 0.3 to 4.0% by weight based on the weight of the polystyrene resin .

As described above, graphite powder, titanium oxide, a flame retardant, and a nucleating agent, which are additives to the polystyrene resin, are put into an extruder and melted. As the extruder, an extruder generally used in this field can be used, and it is also preferable to melt at 180 to 240 캜 so that all of the input materials can be melted.

Subsequently, a step of putting the foaming agent into the molten melt and extruding is carried out.

Here, the foaming agent is used for sufficiently foaming the polystyrene resin, and the foaming agent is preferably used in a range of 3 to 15% by weight based on the weight of the polystyrene resin. When the foaming agent is used in an amount of less than 3% by weight, the polystyrene resin can not be sufficiently foamed to increase the density of the product. When the amount of the foaming agent is more than 15% by weight, a loss of foaming agent occurs.

The extrusion may be extruded through a conventional method in this field, preferably at a temperature of from 100 to 140 < 0 > C.

The blowing agent is any one of H ₂ O, alcohol, pressurized and liquefied HCFCs (HCFC-22, HCFC-142b), butane, CO _{2 and} DME (CH ₃ OCH ₃ ) Is monochloro difluoro methane, and HCFC-142b is Monochloro difluoro ethane.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the present invention is not limited to the following Examples.

Comparative Example  One

3 kg of a flame retardant (HBCD) and 1 kg of a nucleating agent were mixed and injected into 100 kg of a polystyrene resin (LG Chem 25HRE) injected into an extruder and melted at 220 ° C. Then 6 kg of foaming agent HCFC-22 was added and 1 kg of CO ₂ was added to 120 Lt; 0 > C to form a styrene foam.

Comparative Example  2

0.3 kg of graphite powder (density of 30 g / l) as an additive, 3 kg of flame retardant (HBCD) and 1 kg of a nucleating agent were mixed and injected into 100 kg of a polystyrene resin (LG Chem 25HRE) put into an extruder and then melted at 220 캜. And 1 kg of CO ₂ was added thereto. The mixture was cooled and extruded at 120 ° C to prepare a styrene foam.

Example  One

0.3 kg of graphite powder (30 g / l density), 0.2 kg of titanium oxide (Germany Hertzman TR28), 3 kg of flame retardant (HBCD) and 1 kg of a nucleating agent were added to 100 kg of polystyrene resin (LG Chem 25HRE) Then, 6 kg of foaming agent HCFC-22 was added, 1 kg of CO ₂ was added, and the mixture was cooled and extruded at 120 ° C to prepare a styrene foam.

Test Example  One

The density of the styrene foam obtained in Comparative Example 1 (no graphite and titanium oxide), Comparative Example 2 (graphite only) and Example 1 (graphite and titanium oxide added) were measured and the thermal conductivity was measured. Table 1 shows the results.

Thermal conductivity test method: Measured with KS L 9016 at an average temperature of 20 ± 5 ℃

Comparative Example 1 Comparative Example 2 Example 1 density 30g / ℓ 30g / ℓ 30g / ℓ Thermal conductivity 0.0253 W / mK 0.0232 W / mK 0.0237 W / mK

Test Example  2

The styrene foam obtained in Comparative Example 1, Comparative Example 2 and Example 1 was made into a board having a thickness of 50 mm, a width of 900 mm, and a length of 1800 mm, and these were photographed and shown in FIG. 2. The deflection (mm) Were measured. Comparative Example 2 (charging of graphite particles) was 8 mm, and Example 1 (charging of graphite particles + titanium oxide) resulted in 3.5 mm bending in Comparative Example 1 (no addition) in the longitudinal direction of the board when 54 hours elapsed from exposure to the outside. The details are shown in Table 2 below.

Elapsed time
(External temperature in measurement) Comparative Example 1 Comparative Example 2 Example 1 0 hours (30 DEG C) 0mm 0mm 0mm 6 hours (36.5 ° C) 0mm 0mm 0mm 30 hours (37 DEG C) 1mm 3mm 1.5mm 54 hours (37 DEG C) 2mm 8mm 3.5mm

From the above Tables 1 and 2, the thermal conductivity of Example 1 using graphite and titanium oxide at the same time was lower than that of Comparative Example 1, and the deflection was significantly lower than that of Comparative Example 2, and the thermal conductivity And it was confirmed that they were similar to those of Comparative Example 1 in which no graphite was added.

Also, as shown in FIG. 2, it can be seen that the board of Example 1 according to the present invention has no warpage as compared with the board of Comparative Example 2.

Claims (4)

0.1 to 5% by weight of graphite powder and 0.1 to 1% by weight of graphite powder, 0.1 to 1% by weight of graphite powder, 0.1 to 1% by weight of flame retardant, 1 to 5% by weight of HBCD (Hexa bromocyclo dodecane) and 0.3 to 4% Melting; And
Adding 3 to 15% by weight of a foaming agent to the melt to the weight of the resin, and extruding the melt,
Wherein the titanium oxide is a white powder having a density of 0.4 to 1.2 g / m < 2 >. The method for producing an extruded styrene foam according to any one of claims 1 to 3, delete The method according to claim 1,
Wherein the graphite has a density of 20 to 40 g / l. The method for producing an extruded styrene foam according to claim 1, The method according to claim 1,
Wherein the graphite powder is one of natural graphite or synthetic graphite (artificial graphite), and the flame retardant HBCD (Hexa bromocyclo dodecane) is any one of expanded polystyrene foam (EPS) or extruded polystyrene foam (XPS) is TALC, is selected from the group consisting of calcium carbonate and silica, the foaming agent is H ₂ O, an alcohol, pressure granulation to a liquefied state HCFC acids (HCFC-22, HCFC-142b ), butane, CO2 and DME (CH3COCH3) Wherein the extruded styrene foam is excellent in heat insulation and does not cause deformation during outdoor exposure.

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