KR101676742B1 - styrene-form using blowing agent compromising carbon dioxide with excellent insulation and a manufacturing method thoereof - Google Patents

Abstract

The present invention relates to a method for producing a styrene foam and an extruded styrene foam by extruding a foaming agent containing a flame retardant, a nucleating agent and liquefied carbon dioxide to a polystyrene resin as a main raw material.
The extruded styrene foam according to the present invention comprises 100 parts by weight of a polystyrene resin, 1 to 5 parts by weight of a flame retardant, 0.3 to 4 parts by weight of a nucleating agent, 0.2 to 1 part by weight of a carbon dioxide blowing agent and 3 to 10 parts by weight of another blowing agent.

Description

TECHNICAL FIELD [0001] The present invention relates to an extruded styrene foam which is excellent in heat insulation using a foaming agent containing carbon dioxide, and a method of producing the extruded styrene foam.

The present invention relates to an extruded styrene foam excellent in heat insulation property and a method for producing the extruded styrene foam. More particularly, the present invention relates to an extruded styrene foam obtained by mixing a blowing agent containing a flame retardant, a nucleating agent and liquefied carbon dioxide with a polystyrene resin as a main raw material, And a method of producing the foam.

A foamed polystyrene foam board, which is generally used for insulation, is manufactured such that the thermal conductivity value of the foam board is minimized in order to increase the heat insulation efficiency. Typically, it has a density of about 30 g / l as a density that minimizes the thermal conductivity of the foam board. However, in order to save the space and the material of the styrene foam board, a styrene foam having a lower density has been required. However, when the density of the styrene foam is low as described above, the heat insulating performance of the styrene foam is drastically reduced, resulting in a problem that the requirement of the thermal conductivity grade 035 (DIN 18 164, Part 1) is not satisfied.

Techniques for using carbon dioxide foams have been developed to produce styrene foam having a low density and high heat insulating performance. However, in the case of the carbon dioxide blowing agent, the solubility of the carbon dioxide blowing agent with respect to the polystyrene resin is lower than that of the conventional blowing agent of the HCFC type, which requires a high pressure during mixing, so that it is difficult to put the carbon dioxide blowing agent into practical use without replacing equipment such as an extruder. Further, in the case of using a carbon dioxide blowing agent, since the effective diffusion rate and the permeation coefficient of carbon dioxide are high and the activity is high, it is easily replaced with air without remaining on the foam board, thereby increasing the thermal conductivity of the prepared styrene foam there was.

Korean Patent Laid-Open Publication No. 10-2009-0038314 (entitled: Expandable polystyrene beads and a manufacturing method thereof, published on Apr. 20, 2009)

It is an object of the present invention to provide an extruded styrene foam having a reduced density and thermal conductivity of an expanded polystyrene foam, good processing characteristics and good physical properties, and at the same time having excellent heat insulation property and a method for producing the extruded styrene foam.

In order to solve the above-mentioned problems, the styrene foam having excellent heat insulation properties according to the present invention is characterized by comprising 100 parts by weight of a polystyrene resin, 1 to 5 parts by weight of a flame retardant, 0.3 to 4 parts by weight of a nucleating agent, 0.2 to 1 part by weight of a carbon dioxide blowing agent, To 10 parts by weight.

At this time, the carbon dioxide blowing agent and the other blowing agent are charged under the conditions of a pressure of 1550 to 1650 psi and a temperature of 180 to 210 ° C for the melted material obtained by mixing the polystyrene resin, the flame retardant and the nucleating agent, .

At this time, the melt blown into the carbon dioxide blowing agent and the other blowing agent is extrusion-molded under the conditions of a pressure of 900 to 1000 psi and a temperature of 100 to 120 ° C.

At this time, the other foaming agent is any one of hydrogen fluoride carbon (HCFC), hydrogen fluoride (HFC), ethanol, and dimethyl ether.

At this time, the nucleating agent is characterized by being either talc, calcium carbonate or silica.

At this time, the flame retardant is characterized by being hexabromocyclododecane (HBCD) as a brominated flame retardant.

In this case, the carbon dioxide blowing agent has a foaming contribution of 10 to 30%.

In the meantime, the method for producing a styrene foam according to the present invention comprises: mixing 1 to 5 parts by weight of a flame retardant and 0.3 to 4 parts by weight of a nucleating agent to 100 parts by weight of a polystyrene resin; A blowing agent injecting step of injecting 0.2 to 1 part by weight of a carbon dioxide blowing agent and 3 to 10 parts by weight of other blowing agent into the melted material in the melting step under the conditions of a first extrusion pressure and a first extrusion temperature; A cooling step of cooling the melt obtained in the step of injecting the foaming agent; And an extrusion molding step in which the extruded molded styrene foam is extruded at a second extrusion pressure and a second extrusion temperature after being injected into the mold after the cooling step.

In this case, the first extrusion pressure is 1550 to 1650 psi, and the first extrusion temperature is 180 to 210 ° C.

In this case, the second extrusion pressure is 900 to 1000 psi and the second extrusion temperature is 100 to 120 ° C.

At this time, the other foaming agent is any one of hydrogen fluoride carbon (HCFC), hydrogen fluoride (HFC), ethanol, and dimethyl ether.

At this time, the nucleating agent is characterized by being either talc, calcium carbonate or silica.

At this time, the flame retardant is characterized by being hexabromocyclododecane (HBCD) as a brominated flame retardant.

At this time, the carbon dioxide blowing agent has a foaming contribution of 10 to 30%.

The present invention as described above has an effect of forming a polystyrene foam having a low density and a low thermal conductivity while using a carbon dioxide blowing agent to have good processing characteristics and good physical properties.

Further, according to the present invention, ozone destruction and warming, which are problems of conventional foaming agents, can be improved by using a carbon dioxide foam.

FIG. 1 is a flow chart showing steps of a method for producing an extruded styrene foam having excellent heat insulation properties according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are intended to illustrate the present invention in a manner that will be readily apparent to those skilled in the art. And this does not mean that the technical idea and scope of the present invention are limited.

The extruded styrene foam according to the present invention comprises 100 parts by weight of a polystyrene resin, 1 to 5 parts by weight of a flame retardant, 0.3 to 4 parts by weight of a nucleating agent, 0.2 to 1 part by weight of a carbon dioxide blowing agent and 3 to 10 parts by weight of another blowing agent.

The polystyrene (PS) resin used in the present invention is a thermoplastic polymer, and any kind of polystyrene that can be used in the extrusion process can be used. Preferably, polystyrene having a molecular weight of 210,000 to 300,000 g / mol is mainly used. The recycled styrofoam polystyrene polymer may be used in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polystyrene resin used as a main material. However, in the case of extruded styrene foam produced from a recycled styrofoam polystyrene polymer, the extruded styrene foam should be used within a range that does not deteriorate the heat insulating properties of the styrene foam due to the formation of open cells or the like, Do not be anxious.

The flame retardant used in the present invention is preferably a bromine-based flame retardant. As the brominated flame retardant, hexabromocyclododecane (HBCD) may be used. The HBCD is an organic halogen flame retardant, and may be an expanded polystyrene foam (EPS) or an extruded polystyrene foam (XPS) based on polystyrene It can be used mainly. The flame retardant may be added in powder form, or it may be mixed with a polystyrene resin in a pellet form and introduced into a master batch. The bromine (Br) component contained in the brominated flame retardant penetrates into the foamed polystyrene foam board to generate a nonflammable gas, thereby causing digestion. The brominated flame retardant activates the flame retarding mechanism of the polystyrene foam board so that the polystyrene foam itself has self-extinguishing properties.

The flame retardant contained in the extruded styrene foam produced according to the present invention is preferably used in an amount of 1 to 5 parts by weight based on 100 parts by weight of polystyrene. When the flame retardant is used in an amount less than 1 part by weight, the produced extruded styrene foam does not satisfy the flammability criterion specified in KS M 3808, and the flame retardant is poor in terms of combustibility. When the flame retardant is used in an amount exceeding 5 parts by weight, Which is uneconomical and has a problem of deteriorating physical properties such as strength and thermal conductivity of styrene foam.

The crude nucleating agent used in the present invention is any one of talc (TALC), calcium carbonate, and silica, and complements the heat insulating property of the polystyrene foam in the process of producing the expandable polystyrene polymer by the extrusion method. The crude nucleating agent is used to reduce or uniformize the size of the foamed cells. The amount of the nucleating agent used is preferably 0.3 to 4 parts by weight based on 100 parts by weight of the polystyrene resin.

The flame retardant and the nucleating agent are introduced into a primary extruder containing the polystyrene resin, mixed with the polystyrene resin, and then melted.

The carbon dioxide (CO ₂ ) foaming agent used in the present invention induces foaming of the polystyrene resin. The carbon dioxide blowing agent has a foaming power corresponding to 10 to 30%. That is, the carbon dioxide blowing agent has foaming power of 2 to 4 times as much as that of other blowing agents, so that the foaming power of the carbon dioxide blowing agent is high in weight, which is economically advantageous.

The amount of the carbon dioxide foam is preferably 0.2 to 1 part by weight per 100 parts by weight of the polystyrene resin. When the carbon dioxide foam is used in an amount of less than 0.2 part by weight, the amount of the carbon dioxide foam is very small and deviates from the input facility limit. On the other hand, when the above-mentioned carbon dioxide foam is used in an amount exceeding 1 part by weight, the density of the prepared styrene foam increases and the thermal conductivity becomes high, so that the thermal conductivity standard stipulated in KS M 3808 is not satisfied, Open cells are generated in the styrene foam board, resulting in uneconomical problems, and it is difficult to obtain a flat plate of the styrene foam board.

Other blowing agents used in the present invention include HCFC-22 (chlorodifluoromethane), HCFC-142b (chlorodifluoroethane, Monochloro difluoro ethane), HFC Hydrofluorocarbons (HFCs) such as HFC-152a (difluoroethane), HFC-134a (tetrafluoroethane), ethanol and dimethyl ether (DME) can be used. The other foaming agent is preferably used in an amount of 3 to 10 parts by weight based on 100 parts by weight of the polystyrene resin.

The carbon dioxide blowing agent and the other blowing agent are compressed and introduced into a liquefied state at a high pressure and a high temperature condition in a primary extruder containing a melt composed of a polystyrene resin, a flame retardant and a nucleating agent. Preferably, the pressure can be in the range of 1550 to 1650 psi and the temperature is in the range of 180 to 210 ° C. More preferably, the pressure may be 1600 psi and the temperature may be 200 < 0 > C. If the pressure value applied to the primary extruder exceeds 1,650 psi or the temperature value is set to less than 180 ° C, the extrusion equipment is overloaded to reach the facility limit, thereby inhibiting the extrusion quantity, When the pressure value is less than 1,550 psi or the temperature value exceeds 210 DEG C, the carbon dioxide blowing agent is stably dispersed and mixed in the polystyrene resin particles such as GPPS resin, so that a foam having high density and thermal conductivity is produced.

Thereafter, the molten material into which the polystyrene resin, the carbon dioxide blowing agent and the other blowing agent are introduced is cooled in a secondary extruder so as to facilitate foaming, and is then injected into a mold die and extrusion-molded. When extruded, the pressure is preferably 900 to 1000 psi, and the temperature is preferably 100 to 120 ° C. More preferably, the pressure may be 950 psi and the temperature may be 115 < 0 > C. If the pressure value is more than 1000 psi or the temperature value is less than 100 캜 during extrusion, abrasion is promoted due to the limit of the extrusion equipment, while if the pressure value is less than 900 psi or the temperature value exceeds 120 캜, The foaming agent is first foamed before being extruded to form an open cell in the foam, resulting in deterioration of the surface quality of the molded article.

The extruded styrene foam having excellent heat insulation properties according to the present invention can be produced by differently changing the temperature and pressure conditions in the process of producing the conventional styrene foam to remarkably reduce the density and especially the thermal conductivity of the polystyrene foam and to provide good processing characteristics and good physical properties Have

Hereinafter, a method for producing styrene foam having excellent heat insulation properties according to the present invention will be described with reference to FIG.

FIG. 1 is a flow chart showing steps of a method for producing an extruded styrene foam having excellent heat insulation properties according to the present invention.

1, in order to produce styrene foam having excellent heat insulation properties according to the present invention, first, 100 parts by weight of a polystyrene resin is mixed with 1 to 5 parts by weight of a flame retardant and 0.3 to 4 parts by weight of a nucleating agent and melted (S10, step). Specifically, 1 to 5 parts by weight of a flame retardant and 0.3 to 4 parts by weight of a nucleating agent are mixed and melted in a primary extruder containing 100 parts by weight of a polystyrene resin. The polystyrene (PS) resin used herein is a thermoplastic polymer, and any kind of polystyrene that can be used in the extrusion process can be used. Preferably, polystyrene having a molecular weight of 210,000 to 300,000 g / mol is mainly used. The recycled styrofoam polystyrene polymer may be used in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polystyrene resin used as a main material.

The flame retardant introduced into the primary extruder in the step S10 is preferably a bromine-based flame retardant. As the brominated flame retardant, hexabromocyclododecane (HBCD) may be used. The HBCD is an organic halogen flame retardant, and may be an expanded polystyrene foam (EPS) or an extruded polystyrene foam (XPS) based on polystyrene It can be used mainly. The flame retardant may be added in powder form, or it may be mixed with a polystyrene resin in a pellet form and introduced into a master batch. The bromine (Br) component contained in the brominated flame retardant penetrates into the foamed polystyrene foam board to generate a nonflammable gas, thereby causing digestion. The brominated flame retardant activates the flame retarding mechanism of the polystyrene foam board so that the polystyrene foam itself has self-extinguishing properties. The flame retardant contained in the extruded styrene foam produced according to the present invention is preferably used in an amount of 1 to 5 parts by weight based on 100 parts by weight of polystyrene. When the flame retardant is used in an amount less than 1 part by weight, the produced extruded styrene foam does not satisfy the flammability criterion specified in KS M 3808, and the flame retardant is poor in terms of combustibility. When the flame retardant is used in an amount exceeding 5 parts by weight, Which is uneconomical and has a problem of deteriorating physical properties such as strength and thermal conductivity of styrene foam.

The coarse nucleating agent to be fed into the primary extruder in step S10 is any one of talc (TALC), calcium carbonate, and silica, and the insulation property of the polystyrene foam is complemented in the process of producing the expandable polystyrene polymer by the extrusion method. The crude nucleating agent is used to reduce or uniformize the size of the foamed cells. The amount of the nucleating agent used is preferably 0.3 to 4 parts by weight based on 100 parts by weight of the polystyrene resin.

After the step S10, 0.2 to 1 part by weight of the carbon dioxide blowing agent and 3 to 10 parts by weight of the blowing agent are compressed and introduced into the liquefied state under the first extrusion pressure and the first extrusion temperature condition with respect to the molten material melted in the step S10 S20, foaming agent adding step). Specifically, the foaming agent is dispersed among the polystyrene resin particles by injecting a carbon dioxide blowing agent and other blowing agent into the primary extruder containing the melt obtained in the step S10 by using a pump or the like. At this time, the first extrusion pressure is 1550 to 1650 psi, and the first extrusion temperature is 180 to 210 ° C. At this time, the primary extrusion pressure is 1600 psi, and the primary extrusion temperature is more preferably 200 < 0 > C. If the pressure value applied to the primary extruder exceeds 1,650 psi or the temperature value is set to less than 180 ° C, the extrusion equipment is overloaded to reach the facility limit, thereby inhibiting the extrusion quantity, When the pressure value is less than 1,550 psi or the temperature value exceeds 210 DEG C, the carbon dioxide blowing agent is stably dispersed and mixed in the polystyrene resin particles such as GPPS resin, so that a foam having high density and thermal conductivity is produced.

The carbon dioxide (CO ₂ ) blowing agent introduced in the step S20 is used to induce foaming of the polystyrene resin. The carbon dioxide blowing agent has a foaming power corresponding to 10 to 30%. That is, the carbon dioxide blowing agent has foaming power of 2 to 4 times as much as that of other blowing agents, so that the foaming power of the carbon dioxide blowing agent is high in weight, which is economically advantageous.

The amount of the carbon dioxide foam is preferably 0.2 to 1 part by weight per 100 parts by weight of the polystyrene resin. When the carbon dioxide foam is used in an amount of less than 0.2 part by weight, the amount of the carbon dioxide foam is very small and deviates from the input facility limit. On the other hand, when the above-mentioned carbon dioxide foam is used in an amount exceeding 1 part by weight, the density of the prepared styrene foam increases and the thermal conductivity becomes high, so that the thermal conductivity standard stipulated in KS M 3808 is not satisfied, Open cells are generated in the styrene foam board, resulting in uneconomical problems, and it is difficult to obtain a flat plate of the styrene foam board.

The other blowing agents introduced in step S20 are HCFC-22 (chlorodifluoromethane), HCFC-142b (chlorodifluoroethane, Monochloro difluoro ethane), HFC Any one of HFC-152a (difluoroethane), HFC-134a (tetrafluoroethane, Tetrafluoro ethane), ethanol, and DME (Di-Methyl Ether) . The other foaming agent is preferably used in an amount of 3 to 10 parts by weight based on 100 parts by weight of the polystyrene resin.

After step S20, the melt containing the carbon dioxide blowing agent and other blowing agent obtained in step S20 is cooled (S30, cooling step). The melt is then uniformly cooled to facilitate foaming control of the foam thereafter in the extrusion step.

After the step S30, the polystyrene resin and the mixture of the blowing agent cooled in step S30 are put into a mold, extruded and foamed under a second extrusion pressure and a second extrusion temperature to form an extruded styrene foam as a foam (S40, extrusion molding step) . The second extrusion pressure may be 900-1000 psi, and the second extrusion temperature may be 100-120 < 0 > C. More preferably, the second extrusion pressure may be 950 psi and the second extrusion temperature may be 115 캜. If the pressure value is more than 1000 psi or the temperature value is less than 100 캜 during extrusion, abrasion is promoted due to the limit of the extrusion equipment, while if the pressure value is less than 900 psi or the temperature value exceeds 120 캜, The foaming agent is first foamed before being extruded to form an open cell in the foam, resulting in deterioration of the surface quality of the molded article.

The present invention significantly reduces the density and in particular the thermal conductivity of the polystyrene foam by varying the temperature and pressure conditions in the process of making conventional styrene foam, and has good processing characteristics and good physical properties.

Hereinafter, the styrene foam having excellent heat insulation properties according to the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

Example

3 kg of a flame retardant HBCD and 1 kg of a nucleating agent TALC were added to 100 kg of a polystyrene resin ('25 SPE' produced by LG Chemical Co., Ltd.) and melted. Then, under the conditions of a first extrusion temperature of 210 ° C. and a pressure of 1,600 psi, 0.8 kg , 0.5 kg of ethanol and 7 kg of HCFC22,142b, and extruded and foamed at a secondary extrusion temperature of 120 DEG C and a pressure of 950 psi to prepare an extruded polystyrene foam.

Comparative Example

3 kg of the flame retardant HBCD and 1 kg of the same nucleating agent TALC as in the Example were added to 100 kg of a polystyrene resin ('25 SPE' produced by LG Chemical Co., Ltd.), melted and then subjected to a primary extrusion pressure of 1,300 psi 0.8 kg of carbon dioxide blowing agent and 7 kg of HCFC22,142b were charged under the condition of 220 占 폚 and extruded and foamed at a secondary extrusion pressure of 750 psi and a temperature of 120 占 폚 to prepare expanded polystyrene foam.

Test Example

Test results obtained by measuring the density and thermal conductivity of the styrene foam foam obtained from Examples and Comparative Examples and examining the surface condition are shown in Table 1 below. The thermal conductivity of the foam of styrene foam was measured according to Korean Industrial Standard KS L 9016 at an average temperature of 20 ± 5 ° C.

division Example Comparative Example density 31g / l 36g / l Initial thermal conductivity 0.0256 W / mK 0.0297 W / mK surface Good Open cell

As shown in Table 1, in the case of the styrene foam produced by extruding under the pressure and temperature conditions according to the present invention, the density and the initial thermal conductivity are very low, unlike the comparative example. That is, it can be seen that the density and the thermal conductivity level of the styrene foam prepared below the above value are drastically decreased at the primary extrusion pressure of 1550 psi and the secondary extrusion pressure of 900 psi. It can be seen that the density and the thermal conductivity of the styrene foam prepared above the above value are drastically reduced with the primary extrusion temperature of 210 ° C and the secondary extrusion temperature of 120 ° C as a boundary.

Also, the styrene foam of the comparative example prepared under the conditions of the first extrusion pressure of 1550 psi, the second extrusion pressure of 900 psi or less, the first extrusion temperature of 210 캜 and the second extrusion temperature of 120 캜 or more, It can be easily predicted that the thermal conductivity value is rapidly increased by forming a porous foam. On the other hand, it can be confirmed that the surface state of the styrene foam of the example manufactured within the numerical range of the pressure and the temperature according to the present invention is good. That is, a styrene foam having a high quality is produced because the open cell does not occur on the surface of the styrene foam produced at a value below the value of the first extrusion pressure of 1550 psi and the secondary extrusion pressure of 900 psi.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. The present invention is not limited by the examples and the accompanying drawings.

Claims (14)

1 to 5 parts by weight of a flame retardant, 0.3 to 4 parts by weight of a nucleating agent, and 0.2 to 1 part by weight of a carbon dioxide blowing agent having a blowing contribution of 10 to 30%, 3 to 10 parts by weight of a hydrogen fluoride carbon (HCFC ) Or a hydrogen fluoride (HFC) type blowing agent.
The method according to claim 1,
Wherein the carbon dioxide blowing agent and the other blowing agent are introduced at a pressure of from 1550 to 1650 psi and at a temperature of from 180 to 210 캜 for a melt obtained by mixing the polystyrene resin, the flame retardant and the nucleating agent, Styrene foam.
3. The method of claim 2,
Wherein the melt blown into the carbon dioxide blowing agent and the blowing agent is extruded at a pressure of 900 to 1000 psi and a temperature of 100 to 120 ° C.
delete The method according to claim 1,
Wherein the crude nucleating agent is either talc, calcium carbonate or silica.
The method according to claim 1,
Wherein said flame retardant is hexabromocyclododecane (HBCD) as a brominated flame retardant.
delete 1 to 5 parts by weight of a flame retardant and 0.3 to 4 parts by weight of a nucleating agent are mixed with 100 parts by weight of a polystyrene resin and melted;
0.2 to 1 part by weight of a carbon dioxide blowing agent having a blowing contribution of 10 to 30% and 3 to 10 parts by weight of a hydrogen fluorocarbon (HCFC) type or hydrogen fluoride (HFC) type blowing agent to the molten material melted in the melting step A blowing agent introducing step of introducing the blowing agent at a first extrusion pressure and a first extrusion temperature;
A cooling step of cooling the melt obtained in the step of injecting the foaming agent; And
And an extrusion molding step of extruding the extruded styrene foam under a second extrusion pressure and a second extrusion temperature condition after being injected into a mold after the cooling step,
Wherein the first extrusion pressure is from 1550 to 1650 psi, the first extrusion temperature is from 180 to 210 캜,
Wherein the second extrusion pressure is 900 to 1000 psi and the second extrusion temperature is 100 to 120 < 0 > C.
delete delete delete 9. The method of claim 8,
Wherein the crude nucleating agent is any one of talc, calcium carbonate, and silica.
9. The method of claim 8,
Wherein the flame retardant is hexabromocyclododecane (HBCD) as a brominated flame retardant.
delete

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