KR100609838B1 - Method for manufacturing impact sound insulation materials based on styrenic polymer, styreic polymer foam molding manufactured by the method and floating floor structure using the styreic polymer foam molding - Google Patents

Abstract

The present invention relates to a method for producing a sound insulating material using a styrene-based polymer, a styrene-based polymer molded article produced by the same, and a floating bottom structure using the styrene-based polymer molded article, more specifically, a density of 50 kg / preparing primary foam particles that are less than or equal to m ³ ; Exposing and aging the primary foam particles to steam to produce secondary foam particles having a density of 12 kg / m ³ or less; Forming a foam molded body having a density of 10 kg / m ³ or less by molding the secondary foam particles; It characterized in that it comprises the step of compressing and softening the foam molded product so as to have a compression modulus of less than 240kPa, and relates to a styrene-based polymer molded article produced by this method and a floating structure using the styrene-based polymer molded article .

Styrene-based polymer, sound insulation, foam

Description

Manufacture method of sound insulation material using styrene polymer, styrene polymer molded body produced by this and floating bottom structure using this styrenic polymer molded body based on styrenic polymer, styreic polymer foam molding manufactured by the method and floating floor structure using the styreic polymer foam molding}

1 is a view showing the overall process for producing a low modulus of elasticity material according to the present invention,

2 is a view showing a direct extrusion method of a method for producing primary foam particles in the present invention,

3 is a view showing a steam expansion method of the expandable styrene-based polymer beads produced by the extrusion process of the method for producing primary foam particles in the present invention,

Figure 4 is a view showing a steam expansion method of a conventional EPS produced by the suspension polymerization of the method for producing primary foam particles in the present invention,

5 is a view showing a molding process for producing a sound insulating material using a styrene-based polymer according to the present invention.

The present invention relates to a method for producing a sound insulating material using a styrene-based polymer, a styrene-based polymer molded article produced by the same, and a floating bottom structure using the styrene-based polymer molded article.

In general, methods for producing ultra low density foams are known which inflate foamed polystyrene particles several times or secondaryly extruded particulate foam. In the first method, the polystyrene particles impregnated with the blowing agent are extruded without foaming, and then expanded with steam several times to produce foam particles having a density of 10 kg / m ³ or less, and used as a packaging material. In the second method, the extruded foam particles are second expanded to prepare foam particles having a density of 10 kg / m ³ or less and used as a packaging material. For example, U.S. Pat. No. 4,663,360 discloses a foam extruded from a modified polystyrene resin to which a small amount of azido-functional silane is added, thereby expanding the foam at a rate of 5 kg / m ³ or less (expansion ratio 210 or more). A method for obtaining ultra low density foams is described, and US Pat. No. 4,661,302 describes a method for obtaining a similar ultra low density foam from a mixture of polystyrene and a small amount of polyphenylene resin.

However, in this prior art, there is no known method for forming an ultra low density particulate foam while maintaining a low density into a useful molding. Typically, particulate foams obtained by inflation several times have a low foam partial pressure and thus do not expand sufficiently to fill the gaps between the particles during molding. Therefore, in order to mold such ultra low density particulate foam, a molding method different from the existing method should be used.

Polystyrene foam moldings, on the other hand, are used as cushioning materials in "floating floor structures" designed to reduce the transmission of impact noise. In the case of such a floating bottom structure, in general, the lower the dynamic modulus of elasticity of the cushioning material, the greater the noise reduction effect. In order to lower the dynamic modulus of elasticity of the molded article, a method of compressing and softening the molded article to about 20-30% at a time is commonly used.

As such, the process of compressing and softening the polystyrene foam molding to lower the dynamic modulus of elasticity is called 'elastification' or 'compression softening'. In general, when the polystyrene foam is high in density, the polystyrene foam is hard due to the physical properties of the raw material resin, and the deformation is hardly recovered even after pressing the polystyrene foam under pressure. However, if the density of the polystyrene foam is lowered to about 8 kg / m ³ or less, the bubble wall becomes thin and recovers well after compression, and even if the density is slightly higher to 8 to 14 kg / m ³ , once the bubble wall is slightly broken, The foam becomes elastic. That is, since some of the bubble walls are broken by compression, but almost all bubbles remain as independent bubbles, they are easily recovered by the repulsive pressure of the internal air even when pressed and deformed. As such, the polystyrene foam has a low density and then is compressed so that the foam has a low modulus and elastic force.

In addition, the cushioning material used in the floating floor structure must have a load resistance because it receives both the screed load due to the flooring material placed on the floor structure and the traffic load due to human traffic. In general, the elastic modulus and the load-bering capability are related to each other, so it is necessary to check whether the cushioning material having the low modulus has sufficient load resistance.

As indicated in the European Standards EU 1991-2-1, the flooring load (including foam concrete, mortar and floor finishes) is less than 1 kPa, but in some cases the traffic load is 5 kPa. EU 1991-2-1 defines traffic loads on the floors of private or public buildings. For example, the traffic load in shops is specified as 5kPa, and the traffic load in residential buildings is specified as 2kPa.

In order to define the suitability of the product to be used under these various transit loading conditions, the European Union has elaborated on the compression test method in the European standard EN 12 431. Compressibility is a measure of how well the buffer recovers after pressurization. According to this criterion, compressibility means that the specimen thickness (dL) under almost no load (significant load of 0.25 kPa) and high load (2 minutes under 2 kPa load and 2 minutes under 50 kPa load) Afterwards, it is represented by the difference (dL-dB) of the thickness (dB) measured under a load of 2 kPa, and a product having low compressibility, that is, a product having a good recovery of thickness after receiving a load is preferable.

According to this European standard, shock absorbers with a thickness (dL) of 35 mm or less should have a compressibility of less than 2 mm where the transit load is 2 kPa or less. For example, a 20mm cushion for the floor would have to be deformed by a thickness of 2mm less than the original thickness if the thickness was measured under a light load of 2kPa after a brief application of 50kPa.

The compressibility test in accordance with EN 12 431 shows the resilience of the cushioning material after a temporary load, but in practice the load is often applied over the long term at the floor of a residential building. For example, heavy cabinets or furniture have been in place for long periods of time, so consideration should be given to deformation of the cushioning material against such long-term loads. Such deformation due to long-term load is called creep in physical terms. There is no international standard defined for creep resistance requirements for floor sound insulation, but it is clear that floor cushions should not be overly creep. Basically, creep is affected by the load on the floor and its duration. In general, residential floors receive an average load of about 3.5 kPa and load durations are often several years. In the laboratory, the experimental period is usually measured at 1,000 hours (41.7 days), and the appropriate buffer material has a creep of less than 20%, preferably less than 10%, more preferably less than 5% under 3.5 kPa load in this laboratory measurement. Should be small.

Commercially available compression softened polystyrene foam moldings for impact sound reduction generally have a modulus of elasticity higher than 240 kPa. Such compression-softened polystyrene foam moldings are suitable for reducing light weight impact noise but insufficient for reducing weight impact noise. Lowering the modulus of elasticity by adding compressive softening may have an effect on reducing the weight impact sound, but the load resistance may be a problem. Therefore, the polystyrene foam sound insulation material useful for sound insulation of heavy impact sound must have a low elastic modulus and a load resistance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a method for manufacturing a sound insulating material having a better sound insulating ability to reduce weight impact sound.

In order to achieve the above object of the present invention, a method for producing a sound insulating material using a styrene-based polymer of the present invention, the step of expanding the styrene-based polymer to produce a primary foam particles having a density of 50kg / m ³ or less; Exposing and aging the primary foam particles to steam to produce secondary foam particles having a density of 12 kg / m ³ or less; Forming a foam molded body having a density of 10 kg / m ³ or less by molding the secondary foam particles; It characterized in that it comprises the step of producing a compression elastic modulus to 240 kPa or less by compression-softening the foam molded body.

Here, the primary foam particles are prepared by expanding the styrene-based polymer by an extrusion process using a volatile organic foaming agent, and the primary foam particles are also an expandable styrene-based polymer prepared by an extrusion process or a suspension polymerization reaction. And is produced by exposing the particles to steam.

In addition, the styrene-based polymer is a modified polystyrene made by selecting and adding at least one additive from a plasticizing additive group consisting of mineral oil, azido-functional silane and polyphenylene ether to polystyrene resin or polystyrene. It is characterized by being resin.

In addition, the volatile organic blowing agent is characterized in that the mixture of butane and pentane.

In addition, the method for producing a sound insulating material using the styrene-based polymer is characterized in that it further comprises the step of compressing and softening the foam molded body at least once more than 20%.

In addition, the present invention provides a styrene-based polymer molded body, which is produced by the method for producing a sound insulating material using the styrene-based polymer.

SUMMARY OF THE INVENTION The present invention is directed to providing an elastomeric polymer foam material useful for impact noise isolation, comprising the steps of preparing a particulate foam material made of a styrene-based polymer or the styrene-based polymer mixture mixed with other additives or other polymers, wherein the particulate A low modulus of elasticity by expanding the foam into an ultra low density (ULD) foam, shaping the ultra low density foam particles, and compressing and softening the shaped body so that the molded article has a low dynamic modulus and sufficient creep resistance. And to provide a sound insulating material using a styrene-based polymer having a low creep.

Preferred cushioning materials must satisfy two opposing conditions: low modulus and low creep. To do this, first, a polystyrene foam cushioning material having a low modulus of elasticity should be prepared and examined whether the buffering material also satisfies creep conditions. Polystyrene foam buffers having a low modulus of elasticity can be obtained by making low density foams and compression softening of these foams, which can be obtained by secondary expansion of a foam once expanded. Parameters involved in the production of ultra low density molded articles include the manufacturing process, the choice of polymers and blowing agents, the size of the resin and expanded foam particles, secondary expansion conditions and molding methods. In addition, the utilization step includes not only parameters for manufacturing the ultra low density molded body, but also elasticization parameters including the degree and the number of compressions in the compression softening step.

Hereinafter, the overall process and each process for preparing the low modulus material according to the present invention will be described in detail.

The overall process for producing the low modulus material consists of the production, expansion, molding and compression softening of primary foam particles, as schematically shown in FIG.

Phase 1: Primary Foam  Preparation of Particles

There are three methods for producing primary foam particles according to the present invention, which are (a) direct extrusion method, (b) expansion of the expandable styrene-based polymer beads produced by the extrusion process by steam and ( c) Steam expansion of expandable polymer beads (commonly known as EPS (Expandable polymer beads)) produced by suspension polymerization at least one time.

Hereinafter, the methods will be described in more detail.

(a) direct extrusion

The method is schematically illustrated in FIG. 2, wherein the polystyrene resin used in the method is a general purpose polystyrene resin having a weight average molecular weight (Mw) of 150,000 to 230,000. In some cases, in order to improve the expandability of the resin, a mineral oil, or a fluid modifier such as polyphenylene resin and azido-functional silane, or a plasticizer may be added to the resin. The blowing agent also acts as a plasticizer, so when choosing a blowing agent, a suitable balance must be taken into account between the expansion force and the plasticizing effect.

The blowing agent used in the present method is a relatively high volatile blowing agent such as propane, butane, isobutane is used, it is preferable to mix the blowing agent with a low volatility and a high plasticizing effect such as pentane in an appropriate ratio. At this time, when the primary foam particles are produced by the extrusion method, a volatile organic blowing agent mixed with 40 to 90% by weight of butane and 10 to 60% by weight of pentane is most suitable, and when preparing EPS by suspension polymerization, pentane Volatile organic blowing agents in which 50-100% by weight and butane 0-50% by weight are mixed are suitable.

The amount of blowing agent added is 0.5-5gmole, preferably 0.7-3gmole, more preferably 1-2gmole per kg of polymer. If the foaming agent is added less than 0.5gmole, the foaming ratio of the initial foam is too low to produce a low density primary particulate foam, if the foaming agent is added more than 5gmole it is difficult to maintain the die pressure, There is a problem that the diameter is too small.

In addition, in the present method, a small amount of nucleating agent such as talc powder may be added to control the size of the bubbles.

The foam particles of the invention are prepared by cutting the extruded strand exiting the die at its very outer surface, or by cutting the already expanded foam strand exiting the die. The foam particles have a density lower than 50 kg / m ³ (expansion ratio 21) and preferably have a density lower than 35 kg / m ³ (expansion ratio 30). And the magnitude | size of foam is 0.05-1 mm, Preferably it is 0.2-0.6 mm. The size of the foam particles also affects secondary expandability. The size (diameter) of the foam strand is preferably greater than 2 mm, preferably greater than 5 mm, most preferably 7-12 mm.

(b) Steam Expansion Method of Expandable Styrenic Polymer Beads Prepared by Extrusion Process

The method is schematically illustrated in FIG. 3, which is similar to the method for producing a loose fill. In this method, the process until the foam emerges from the die is similar to the above (a) direct extrusion method, and the resin used is the same as that used in the (a) direct extrusion method.

However, in the present method, unlike the direct extrusion method (a), the molten resin strand exiting the die is quenched immediately in cold water to prevent expansion, and then cut to prepare unexpanded particles. In addition, in this method, a low volatility blowing agent such as n-pentane is used to prevent the molten resin strands from foaming in the die, and the size (diameter of the strands) of the non-expandable particles thus made is larger than about 1.5 mm. . The foamed resin particles are expanded with steam to produce foam particles, which are expanded as many times as necessary until their density is lower than about 20 kg / m ³ (expansion rate 53).

(c) Steam expansion of conventional EPS prepared by suspension polymerization

The method is shown schematically in FIG.

Conventional EPS materials are made of general purpose polystyrenes having a molecular weight of 200,000 to 250,000 and generally comprise 3 to 8% by weight of blowing agent. At this time, the blowing agent is preferably a mixture of 50 to 100% by weight of pentane and 0 to 50% by weight of butane, the amount of blowing agent added is 0.5 to 5gmole, preferably 0.7 to 3gmole per 1 kg polymer, more preferably 1 ~ 2gmole. If the foaming agent is added less than 0.5gmole, the foaming ratio of the initial foam is too low, it is difficult to produce a low-density primary particulate foam, there is a problem that the impregnation is difficult when the foaming agent is added more than 5gmole.

EPS suitable for the present invention uses relatively large particles having a particle size of at least 1.2 mm, preferably at least 1.5 mm. The particles are expanded at least once in steam to produce foam particles having a density lower than about 20 kg / m ³ (expansion 53).

Step 2: Inflate

The foam particles prepared in step 1 and aged for at least 6 hours are expanded with steam until a high expansion rate is obtained. The required steam exposure time depends on the density of the primary foam or the method of making the primary foam, but the steam exposure time to obtain the desired low density foam is 1-10 minutes, typically 2-7 minutes, more generally 3 to 5 minutes. In this secondary expansion stage, the foam reaches an expansion ratio of 85 (density 12.4 kg / m ³ ) or more, preferably an expansion ratio of 100 (density 10.5 kg / m ³ ) or more, more preferably an expansion ratio of 130 (density 8.1 kg / m) m ³ ) or more.

Step 3: Molding

The expanded particulate foam is aged at least 6 hours before the forming step. The molding method includes (a) a conventional EPS molding method or (b) a molding method of polyolefin foam particles.

A method for forming polyolefin foam particles was published in 2004 by Hanseo Publishing Co. in Munich. Klempenner and V. CPPark, "Polyolefin", a chapter in Polymeric Foams and Foam Technology edited by D. Klempner and V. Sendijarevic, 2nd Edition, Hanser Publishers, Munich 2004).

First, (a) in the conventional EPS molding method, the foam particles are filled in the molding mold, softened and expanded by heating with steam, and the gaps between the particles are filled to stick to each other. The molding method of this step can be used when the foam particles have a foaming force that expands by 30% or more by steam.

In addition, (b) the molding method of the polyolefin foam particles is formed by forming the particles in the mold to form the necessary expansion force when the foam particles expanded to a very low density by heating many times when the expansion force is mostly consumed in the particle expansion stage and the expansion force is insufficient. It is a method of reducing the volume of the mold after filling or infiltrating air into the foam bubbles before filling the foam particles in the mold to improve the expansion force.

Step 4. Compression Softening

The molded foam is compression softened to produce a compressive modulus of less than 240 kPa, preferably a compressive modulus of less than 200 kPa, more preferably a compressive modulus of less than 150 kPa. The compressive modulus of elasticity is measured by a method corresponding to ASTM 1621 at a compression rate of 500 mm per minute. Effective compression softening requires compression of at least 25% of the foam thickness, but excessive compression should be avoided to ensure that the foam maintains sufficient creep resistance.

Compression-softened foams according to the present invention have less than 20% creep, preferably less than 10%, and more preferably less than 5% when measured for 1000 hours under a load of 3.5 kPa.

The following specific examples are intended to illustrate the invention and are not intended to limit the scope of the invention. In the examples, parts and percentages are by weight unless otherwise indicated, or unless content is necessary.

Ultra-low Density Particle Type by Extrusion Foam  Produce

This example shows that an ultra low density molded body can be produced from the particle foam produced by the extrusion process.

Foam Extrusion Process

The apparatus used in this embodiment is a tandam foam extrusion line consisting of a primary extruder with twin screws of 30 mm diameter and a cold extruder with a single screw of 40 mm diameter. The primary extruder is a 40D long Leistritz LSM34 model extruder with a mixing section followed by a conventional feed, melt and metering section, and the inlet for blowing agent is located 19D from the resin feed. The primary extruder includes a total of eight heating sections, and the cooling extruder also has three cooling sections in a 40D barrel. At the end of the cold extruder is attached a die orifice with two 1.5 mm diameter circular holes, the land of the die orifice being about 3 mm. In addition, the temperature of the die orifice is controlled by the oil medium as used in the third cooling section.

In practice, the operation starts with all parts of the primary extruder maintained at 200 ° C., and the rotational speed of the screw gradually increases to 40 rpm. The cold extruder set all three parts to 175 ° C. and then started operation to adjust the rotational speed of the screw to 25 rpm. Granular polystyrene having a molecular weight of 170,000 was mixed with the nucleating agent and fed to the extruder at a constant rate of 1.81 kg per hour. Here, the nucleating agent is a mixture of talc powder and barium stearate in a weight ratio of 2: 1, and is added such that the nucleating agent is 0.15 parts by weight (pph) per 100 parts by weight of the resin.

In addition, the foaming agent used in this process is a mixture in which the isobutene: n-pentane mixture is mixed in a ratio of 70:30, and injected into the mixing portion of the extruder so that 7.5 parts by weight of the blowing agent per 100 parts by weight of the resin.

Then, when stable extrusion conditions were achieved, the temperature of the cold extruder cooling section was lowered to 165 ° C., 147 ° C. and 142 ° C., respectively, and finally a good foam strand having a diameter of about 9.5 mm was obtained. The foam produced in this way has a density of about 31.6 kg / m ³ and a bubble size of about 0.4 mm. Several foam strands of about 70 cm length were taken for the next experiment of this example.

Secondary expansion process

After about one day after extruding the foam, the foam strands were cut into lengths of about 14 mm to make cylindrical particles, and the cylindrical particles were exposed several times in a steamer for 1 to 10 minutes to determine the optimum expansion time. Cylindrical foam particles become bulky in the steamer when exposed to steam for a long time, but quickly shrink when taken out of the steamer. The contracted cylindrical foam particles slowly recover in volume during aging at room temperature.

The density of foam particles measured on day 6 after the secondary foaming process with steam is shown in Table 1 below.

Steam exposure time on second expansion (minutes) Density of foam after 6 days of expansion (kg / m ³ ) Coefficient of expansion 0 31.6 33 One 9.4 112 3 5.4 194 4 5.0 212 5 3.9 269 6 3.7 284 10 3.6 292

As can be seen from Table 1, the foam particles expand at very low density by steam. According to Table 1, if the steam exposure time is 3 minutes or more, a foam having a density (expansion rate of 190 or more) of 6 kg / m ³ or less is obtained, and an optimum steam exposure time is 3 to 5 minutes. If the foam is exposed for more than 5 minutes, the expansion ratio is further increased, but the loss of the blowing agent is also large, which is not preferable.

In order to prepare a molding to measure the physical properties, a large amount of foam strands were cut after 4 days from extrusion foaming, wherein the size of each particle was cut so that the length and diameter ratio were equal to each other at 9.5 mm. It was. The foam particles were inflated in a steamer for 3 or 5 minutes, and the density of the foam measured after 3 days from expansion was measured, and the density of the expanded foam for 3 minutes was 6.7 kg / m ³ , 5 The density of the expanded foam in minutes was 6.2 kg / m ³ .

Molding process

Secondary expanded particle foams were aged after at least 6 days and molded. At this time, the aluminum mold used in the molding process, as shown in Figure 5, the cross section is 99mm × 99mm, the height is 101mm, it is possible to adjust the height of the molding cavity (cavity) using a plug. A plug attached to the lid of the mold is used to shrink the height of the mold of the mold from 101 mm to 50 mm in height of 51 mm. In the actual experiment, the foam particles were filled up to the upper part of the mold, and the plug was compressed to close the lid so that the height of the filling was 50 mm. Then, after injecting steam into the filling for about 1 minute, the outer surface of the mold was rapidly cooled and molded. The molded article molded in this way slightly contracted when taken out of the mold, but recovered during aging at room temperature.

Table 2 below shows the results of measuring the density and dimensions of the molded article after molding the secondary expanded foam particles by this step.

Second expansion time (minutes) Density of Foam Particles (kg / m ³ ) Mold Dimension Density of molded body (kg / m ³ ) Display Horizontal (mm) Length (mm) Height (mm) 3 6.7 91 90 41 8.1 XPS.1 5 6.2 92 90 44 8.2 XPS.2

As shown in Table 2, the density of the foam particles after molding can see that the increase to 8.2kg / m ³ at ^{8.7kg / m 3, 6.2kg / m} 3 at each 6.7kg / m ^3.

In the present specification, the molded article molded after the second expansion for 3 minutes is called XPS.1, and the molded article molded after the second expansion for 5 minutes is named XPS.2.

Foam Molded  Compression softening process

In this embodiment, the compression softening experiment of the molded article by compression was conducted using not only the XPS molded article prepared above but also a conventional EPS molded article having a density of 8 kg / m ³ .

A process for preparing a conventional EPS material is as follows. That is, EPS particles of about 2 mm in size are expanded twice with steam to form low-density foam particles, and the particles are placed in a mold, and then the mold is contracted by about 20% of volume and molded by injection of steam. The foam used for the compression softening of this embodiment is a slab slab of 18.7 mm thickness, and for convenience, the EPS molding is referred to herein as EPS8 (EP molding of 8 kg / m ³ density).

The XPS molded body was divided into two pieces of the same thickness by using a hot wire cutter, and the EPS molded body was cut into a sample of about 90 mm x 90 mm and used for compression softening experiments. Compression softening was performed by placing the specimen between two flat plates and compressing it three times at 25 mm to 50% of the specimen thickness at a rate of 100 mm per minute. When compressing the specimen more than once, there was a 5-minute interval between compressions.

The XPS compacts were first compressed twice with 25% compression, secondly with 35% compression, and EPS samples were compressed three times with 30% compression and twice with 50% compression. In the present specification, the name of the substance is denoted by n × m to indicate that the substance is compressed n times by m percent. In other words, XPS.1 2 × 25 × 35 means that XPS.1 is compressed twice, 25% and 35%.

Thickness recovery of the foam specimens was observed after compression, and the results are shown in Table 3 below. The ultra low density foam molded body was elastically recovered more than 88% of its original thickness after one day, and the thickness recovery was basically completed almost one day later.

Aging period after compression XPS.1 2 × 25 × 35 XPS.2 2 × 25 × 35 EPS 8 1 × 30 EPS 8 2 × 30 EPS 8 3 × 30 EPS 8 1 × 50 EPS 8 2 × 50 Right after 77 89 92 91 90 85 83 5 minutes 82 92 95 92 92 88 87 1 day 94 98 94 93 94 90 88 76 days - - 95 93 93 90 88

The measured values in Table 3 represent the recovered thickness as a percentage of the original thickness of the molded body. For example, the thickness measured after 5 minutes of compressing the XPS.1 is 82% of the initial thickness.

Molded  Compression Characteristics Measurement

In this example, the compression characteristics of the compression-softened molded body were measured. In this case, the compressive modulus of elasticity was measured by a method corresponding to ASTM D1621 at two different compression speeds, 20 mm / minute and 500 mm / minute. A high compression speed of 500 mm / minute was used to simulate the dynamic modulus of elasticity. The compressive strength of the molded body was measured at a low compression speed of 20 mm / minute, and creep was measured for 1000 hours under a 3.5 kPa load.

The experimental results of this example are shown in Tables 4 and 5 below. First, Table 4 below shows the characteristics of the uncompressed XPS.1 and XPS.2 and the characteristics of XPS.1 and XPS.2 compressed twice at 25% and 35%.

characteristic Way unit XPS.1 XPS.2 Molding (uncompressed) Compressed 2 × 25 × 35 Molding (uncompressed) Compressed 2 × 25 × 35 Compressive modulus 500mm / m kPa 70 22 79 56 20mm / m kPa 70 30 83 55 Compressive strength 5% strain kPa 2 One 3 One 10% strain kPa 5 3 7 3 25% strain kPa 17 8 19 12 Compression deformation 1000 hours at 3.5 kPa % 12 16 9 20

As shown in Table 4, the uncompressed XPS molded body has a low compressive modulus of less than 85 kPa at both strain rates, and the compressive strength is also very low, 7 kPa or less at 10% or less deformation.

In addition, the compression softened XPS molded product lowers the compressive modulus by one-third of the first to soften the XPS molded product, and the compression softened XPS molded product has a satisfactory creep despite having a very low compressive modulus and a low compressive strength. It shows resistance. Compression-softened XPS moldings show high creep as expected, but it can be seen that they are still within tolerance because they generate less than 20% creep at 1000 hours.

In addition, Table 5 below shows the compressive properties of EPS having a compression softened 8 kg / m ³ density.

characteristic Way unit Uncompressed EPS 8kg / m ³ density compressed EPS of 1 × 30 2 × 30 3 × 30 1 × 50 2 × 50 Compressive modulus 500mm / m kPa 684 352 326 232 194 165 20mm / m kPa 582 300 271 224 239 144 Compressive strength 5% strain kPa 29 15 14 13 12 9 10% strain kPa 42 23 21 21 20 17 25% strain kPa 61 49 45 45 41 37 Compressibility EN 12 431 mm 2.3 1.8 1.8 1.8 1.5 1.6 Compression deformation 1000 hours at 3.5 kPa % -0.1 0.3 0.3 0.1 0.2 0.7

Conventional EPS materials, although low density, are harder than XPS materials. As shown in Table 4 and Table 5, the compressive modulus of the EPS material is almost 10 times higher than the compressibility of the XPS material, and the compressive softening results in the compressive modulus being 1/2 to 1/4 of the original compressive modulus. To decrease. In the case of EPS material compressed three times at 30%, once compressed at 50%, or twice at 50%, the compressive modulus of compressive modulus of 240 kPa or less can be seen at both 20 mm / m and 500 mm / m. have.

In addition, the compressibility of the compression softened material is less than 2 mm, while the compressibility of the original EPS material slightly exceeds the allowable limit of 2 mm. In addition, the compressive softened material shows almost no deformation when subjected to a 3.5 kPa load for 1000 hours, thus leaving room for further elasticization.

Comparative example

This comparative example to measure the maximum limit of the density of the molded foam article that may be used in the present invention, a conventional EPS slab plate compression and softening of the upper body of the EPS 8kg / m ³ density, has a density of about 12.4kg / m ³ Experiment was carried out to measure the compression characteristics as in Example 3, the results are shown in Table 6 below.

characteristic Way unit Uncompressed EPS 12 kg / m ³ compressed EPS 1 × 30 2 × 30 3 × 30 1 × 50 2 × 50 Thickness recovery Immediately % - 88 86 88 79 73 5 minutes later % - 90 90 91 85 77 1 day later % - 92 91 92 86 80 76 days later % - 93 91 92 86 81 Compressive modulus 500mm / m kPa 1540 572 397 368 479 334 20mm / m kPa 1320 570 366 436 456 450 Compressive strength 5% strain kPa 67 28 17 20 21 21 10% strain kPa 81 40 33 33 34 31 25% strain kPa 104 71 64 64 60 56 Compressibility EN 12 431 mm 1.3 1.9 2.2 2.1 2.1 2.0 Compression deformation 1000 hours at 3.5 kPa % 0.2 -0.7 0.6 0.1 -0.2 -0.5

As shown in Table 6, the EPS foamed molded article having a density of 12.4kg / m ^{3 of the} comparative example was less recovered than the EPS of 8kg / m ³ density after compression, and the molded article was too hard to be used as an impact buffer. In addition, the molded body has excellent deformation resistance due to high compressive strength, but the compression softened material exhibits critical compressibility.

Styrene-based polymer molded article according to the present invention is a low-density foam, the compression modulus of less than 240kPa can effectively block the transmission of weight impact noise, and satisfies the load-bearing capacity.

Therefore, the styrene-based polymer molded body according to the present invention can be effectively used for the floor structure floated by utilizing as a sound insulating material between the floor of the building.

Claims (8)

Expanding the styrenic polymer to produce primary foam particles having a density of 50 kg / m ³ or less; Exposing and aging the primary foam particles to steam to produce secondary foam particles having a density of 12 kg / m ³ or less; Forming a foam molded body having a density of 10 kg / m ³ or less by molding the secondary foam particles; Compressing and softening the foamed molded article to produce a compression modulus of 240 kPa or less; Method for producing a sound insulating material using a styrene-based polymer comprising a. The method of claim 1, The primary foam particles are prepared by expanding the styrene-based polymer by an extrusion process using a volatile organic foaming agent. The method of claim 1, The primary foam particles are a method of manufacturing a sound insulating material using a styrene-based polymer, characterized in that the expanded styrene-based polymer particles produced by the extrusion process or suspension polymerization reaction is produced by exposing to steam. The method of claim 1, The styrene-based polymer is a modified polystyrene resin prepared by adding at least one additive selected from a group of plasticizing additives consisting of mineral oil, azido-functional silane, and polyphenylene ether to polystyrene resin or polystyrene. A method for producing a sound insulating material using a styrene polymer. The method of claim 2, The volatile organic blowing agent is a method for producing a sound insulating material using a styrene-based polymer, characterized in that the mixture of butane and pentane. The method of claim 1, Method for producing a sound insulating material using a styrene-based polymer, characterized in that it further comprises the step of compressing and softening the molded article more than 20% at least once. A styrene-based polymer molded article produced by the method according to any one of claims 1 to 6. Floating bottom structure using the styrene-based polymer molded article according to claim 7.

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