KR102139975B1 - Thermoplastic Elastomer Composition For Reducing Floor Impact Sound And Foamed Articles Therefrom - Google Patents

Abstract

A thermoplastic elastomer composition for reducing interlayer noise, comprising: 10 to 30% by weight of ethylene vinyl acetate (EVA); 20 to 55% by weight of polyolefin elastomer (POE); Olefin block copolymer (OBC) 15 to 30% by weight; 15-30% by weight of low density polyethylene (LDPE); And 5 to 15% by weight of styrene-isoprene-styrene스티block copolymer (SIS), wherein the polyolefin elastomer (POE) can be selected from the group consisting of ethylene-octene copolymers, ethylene-butene copolymers, and combinations thereof. have.

Description

Thermoplastic Elastomer Composition For Reducing Floor Impact Sound And Foamed Articles Therefrom}

The present invention relates to a thermoplastic elastomer composition for reducing noise between layers and a foam thereof.

In the case of multi-storey buildings such as apartments and multi-storey buildings, air propagation is mostly blocked by concrete slab structures, but when shock or vibration is directly applied to the floor due to walking or falling objects from the upper floor, it becomes a solid propagation sound. It is changed and hardly attenuated, and has the characteristic of being radiated through a floor slab, ceiling or wall into a lower layer or adjacent generations. This kind of impact sound is called'interlayer noise', and it generates a lot of low-frequency components such as light-weight impact sounds that generate a lot of high-frequency components, such as falling sounds of dishes and objects, and chair movement sounds, and adult walking or children's jumping. It is distinguished by weight impact. In apartment houses, both heavy and light impact sounds are generated, and floor cushioning materials for reducing noise between floors of buildings to prevent its propagation are further required.

The floor cushioning material is required to contain an elastomer having elastic properties, soft touch, excellent impact strength, and heat resistance. For this purpose, a foam obtained by injection molding a thermoplastic elastomer resin composition having foamability is used.

Korean Patent Publication No. 10-2003-0078135 discloses, as an example, a “EVA pad” made of a foam having a composition having EVA as a main material component and LDPE as an auxiliary material component. In addition, in Korean Patent Publication No. 10-2016-0107773, EVA is used as a main material component, but by replacing all or part of LDPE as a material component with LLDPE having a softening point higher than that of LDPE, the long-term maintenance performance of dynamic elasticity is further improved and heat-resistant retention Also disclosed is an EVA composition with improved durability.

However, a buffer material using a conventional EVA as a composition has a phenomenon in which the dynamic elasticity, which is a property of insulating vibration and absorbing sound pressure, rapidly increases with time.

Accordingly, there is a need for an elastomer composition capable of continuously maintaining a dynamic modulus of elasticity for a longer period of time, thereby effectively reducing inter-layer noise generated in buildings such as apartments and apartment houses.

Korean Patent Publication No. 10-2012-0095987 Korean Patent Publication No. 10-2016-0107773

The problem to be solved by the present invention is to provide a thermoplastic elastomer composition and a foam thereof having a constant coefficient of dynamic elasticity before and after heating.

In addition, it is an object of the present invention to provide a thermoplastic elastomer composition and a foam that can be used for a long time after being installed because it has excellent durability and does not cause a phenomenon in which the dynamic elasticity increases rapidly over time.

It is also an object to provide a highly elastic thermoplastic elastomer composition and a foam thereof.

The object of the present invention is not limited to the object mentioned above. Other specific matters of the present invention are included in the detailed description and drawings.

The thermoplastic elastomer composition for reducing inter-layer noise according to the present invention for achieving the above object,

Ethylene vinyl acetate (EVA) 10 to 30% by weight; 20 to 55% by weight of polyolefin elastomer (POE); Olefin block copolymer (OBC) 15 to 30% by weight; 15-30% by weight of low density polyethylene (LDPE); And 5 to 15% by weight of a styrene-isoprene-styrene 중량block copolymer (SIS),

The polyolefin elastomer (POE) may be selected from the group consisting of ethylene-octene copolymers, ethylene-butene copolymers, and combinations thereof.

The ethylene-octene copolymer may be included in an amount of 10 to 25% by weight and the ethylene-butene copolymer in an amount of 10 to 30% by weight based on the total weight of the thermoplastic elastomer composition.

The olefin block copolymer (OBC) comprises an ethylene-octene block copolymer,

In the ethylene-octene block copolymer, a hard ethylene-octene block having an octene content of 2.0% by weight and a soft ethylene-octene block having an octene content of 48.3% by weight may form a copolymer.

In addition, it may further include ethylene propylene rubber (EPDM), the ethylene propylene rubber (EPDM) may be included in 5 to 15% by weight relative to the total weight of the thermoplastic elastomer composition.

Further, zinc oxide (ZnO) may be further included, and the zinc oxide (ZnO) may be included in 1 to 3% by weight based on the total weight of the thermoplastic elastomer composition.

In addition, zinc stearic acid (Zn-St) may be further included, and the zinc stearic acid (Zn-St) may be included in 0.5 to 1.3% by weight based on the total weight of the thermoplastic elastomer composition.

In addition, at least one of a reinforcing agent, a crosslinking agent, and a blowing agent may be further included.

The reinforcing agent may include at least one of talc and calcium carbonate (CaCO ₃ ).

The crosslinking agent may include at least one of [1,3-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide and [1,4-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide have.

The blowing agent may include an azodicarbonamide compound.

In addition, the foam for reducing inter-layer noise according to the present invention can be produced using the thermoplastic elastomer composition.

In addition, the foam may have an uneven shape.

Specific details of other embodiments are included in the detailed description and drawings.

According to the thermoplastic elastomer composition for interlayer noise reduction according to some embodiments of the present invention and its foam, the dynamic elastic modulus is stably maintained even in an environment in which building temperature conditions (approximately 50-70° C.) of an apartment or the like last for a long time.

In addition, since the thermoplastic elastomer composition for reducing noise between layers is low in specific gravity and has excellent flexibility, the elasticity of the foam produced therefrom increases and the buffering effect is improved.

The effects of the present invention are not limited to the effects mentioned above. It should be understood that the effects of the present invention include all effects that can be deduced from the following description.

1 is a cross-sectional side view of an interlayer structure in which a foam is installed according to an embodiment of the present invention.
2 is a cross-sectional side view of an interlayer structure in which a foam is installed according to another embodiment of the present invention.
3 is a side cross-sectional view of an interlayer structure in which a foam is installed according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, and the present invention is only defined by the scope of the claims. The same reference numerals refer to the same components throughout the specification.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used as meanings commonly understood by a person having ordinary skill in the art to which the present invention pertains. In addition, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively, unless specifically defined.

In addition, the terminology used herein is for describing the embodiments and is not intended to limit the present invention. In the present specification, the singular form also includes the plural form unless otherwise specified in the phrase. As used herein, “comprises” and/or “includes” one or more other components, features, numbers, steps and/or actions other than the components, features, numbers, steps and/or actions mentioned It is used in a sense that does not exclude the presence or addition of an action. And, “and/or” includes each and every combination of one or more of the items mentioned.

Unless otherwise specified, all numbers, values, and/or expressions expressing amounts of ingredients, reaction conditions, polymer compositions, and blends used herein are those numbers that occur in obtaining these values, among other things. As these are approximations that reflect the various uncertainties of the measurement, it should be understood that in all cases they are modified by the term "about". In addition, when numerical ranges are disclosed in the present description, these ranges are continuous, and include all values from the minimum value in this range to the maximum value including the maximum value, unless otherwise indicated. Further, when such a range refers to an integer, all integers including the minimum value to the maximum value including the maximum value are included unless otherwise indicated.

In the present specification, when a range is described for a variable, it will be understood that the variable includes all values within the stated range including the described endpoints of the range. For example, a range of “5 to 10” includes values of 5, 6, 7, 8, 9, and 10, as well as any subrange of 6 to 10, 7 to 10, 6 to 9, 7 to 9, and the like. It will be understood to include, and include any value between integers pertinent to the stated range of ranges such as 5.5, 6.5, 7.5, 5.5 to 8.5 and 6.5 to 9, and the like. Also, for example, the range of “10% to 30%” is 10% to 15%, 12% to 10%, 11%, 12%, 13%, etc., and all integers including up to 30%. It will be understood that it includes any subranges such as 18%, 20% to 30%, etc., and also includes any value between valid integers within the scope of the stated range, such as 10.5%, 15.5%, 25.5%, and the like.

Hereinafter, the present invention will be described in more detail according to the accompanying drawings.

The thermoplastic elastomer (buffer) composition for reducing inter-layer noise according to the present invention, ethylene vinyl acetate (Ethylene Vinyl Acetate, EVA) 10 to 30% by weight, polyolefin elastomer (Polyolefin Elastomer, POE) 20 to 55% by weight, olefin block nose Polymer (Olefin Block Copolymer, OBC) 15 to 30 wt%, Low Density Polyethylene (LDPE) 15 to 30 wt% and Styrene-isoprene-styrene Block Copolymer (SIS) 5 to 30 15% by weight.

In the thermoplastic elastomer composition of the present invention, ethylene vinyl acetate has a softening point of 70° C. or higher, and when manufactured in the form of a foam using this, processability is easy and crosslinking efficiency is also excellent. The melting point (TM, Melting Temp) is markedly lowered as the melt index (MI) or the content of vinyl acetate (VA) increases. Accordingly, the compounding workability in the ethylene vinyl acetate resin is largely dependent on the vinyl acetate content, and the higher the content value, the softer the decrease in crystallinity, and the fillability of the additive is greatly improved.

In the thermoplastic elastomer composition of the present invention, the polyolefin elastomer (POE) may be selected from the group consisting of ethylene-octene copolymer, ethylene-butene copolymer, and combinations thereof. Ethylene-octene copolymers and ethylene-butene copolymers are colorless, transparent and odorless. In addition, ethylene vinyl acetate (EVA), polyethylene (PE), polypropylene (PP) or low-density polyethylene (LDPE) compared to low specific gravity and has excellent properties of flexibility. Therefore, the elasticity is increased than the ethylene vinyl acetate foam (EVA Foam) used in the related art, and exhibits a good effect in the coefficient of dynamic elasticity, which is a property that can insulate vibration and absorb sound pressure. Here, the coefficient of dynamic elasticity (s', unit: MN/m ³ ) is a ratio of dynamic displacement to dynamic load, and can be theoretically derived by the following equation (1).

(In Equation 1, S is the area (m ² ) of the test piece, F is the dynamic load (N) applied perpendicularly to the test piece, Δd is the dynamic change value (m) of the test piece thickness).

The dynamic elastic modulus can be measured by sine wave excitation or pulse excitation in an experiment. Meanwhile, the dynamic modulus per unit area may be calculated through the measurement of the natural frequency (or resonance frequency), and the loss coefficient may be calculated from the natural frequency. The natural frequency (f _r , unit: Hz) may be derived by Equation 2 below.

(In Equation 2, s _'t is the apparent dynamic modulus (MN / m ^3), m per unit area of the test specimen' _t is a mass per unit area of the load plate (kg / m ^2), Im).

On the other hand, the cushioning material used for the floor structure is preferably a dynamic modulus of elasticity of 40MN/m ³ or less, and a loss coefficient of 0.1 to 0.3.

Particularly, in the present invention for the desired effect, 10 to 25% by weight of ethylene-octene copolymer copolymer and 10 to 30% by weight of ethylene-butene copolymer based on the total weight of the thermoplastic elastomer composition may be included in the thermoplastic elastomer composition as a polyolefin elastomer. have.

In the thermoplastic elastomer composition of the present invention, since the olefin block copolymer (OBC) is flexible and has excellent heat resistance properties compared to the polyolefin elastomer, a foam (or a buffer material) made of the same is dimensionally stable. This is improved. In addition, since it has high elasticity and resilience, it exhibits excellent properties in residual strain. In addition, when the content of the olefin block copolymer is high and is made of a foam, it is possible to prevent durability degradation due to low specific gravity. However, when the olefin block copolymer is contained in an amount of 50% by weight or more of the total weight of the thermoplastic elastomer composition, the workability of the sheet during processing is significantly reduced, and thus the surface may not be clean. Therefore, it is preferred that 15 to 30% by weight of the olefin block copolymer is included in the total weight of the thermoplastic elastomer composition.

Meanwhile, the olefin block copolymer (OBC) of the present invention may include, for example, an ethylene-octene block copolymer (Blocky Ethylene-Octene Copolymer). The ethylene-octene block copolymer may be formed of a hard block and a soft block copolymer. For example, a light ethylene-octene block having an octene content of 2.0 wt% (or 0.5 mol%) and a soft ethylene-octene block having an octene content of 48.3 wt% (or 18.9 mol%) can form a copolymer. have.

Low-density polyethylene (LDPE) in the thermoplastic elastomer composition of the present invention has the characteristics of excellent transparency, processability, and mechanical strength, and thus exhibits an effect of improving physical properties in a foam manufactured by including it. Such low-density polyethylene, preferably, may contain 10 to 30% by weight of the total weight of the thermoplastic elastomer composition. More preferably, it may contain 15 to 30% by weight.

On the other hand, low-density polyethylene is characterized by relatively low elasticity and high hardness, and thus, when blended with a polyolefin elastomer having high elasticity as in the present invention, a foam for high elasticity can be produced.

In the thermoplastic elastomer composition of the present invention, the styrene-isoprene-styrene　block copolymer (SIS) may have, for example, a content of styrene of 25% by weight or less. This styrene-isoprene-styrene　block copolymer is suitable for peroxide crosslinking (for example, bis(alpha-t-butyl-peroxyisopropyl)benzene (hereinafter, BIPB) is used as a crosslinking agent) It helps to improve the compression set. Thus, for example, when ethylene propylene rubber (EPDM) is included in the thermoplastic elastomer composition, it is possible to compensate for the resilience (deflection), which is a characteristic of ethylene propylene rubber.

When such a styrene-isoprene-styrene　block copolymer contains 15% by weight or more of the total weight of the thermoplastic elastomer composition, the hardness decreases to a degree similar to that of ethylene propylene rubber, and the heat shrinkage increases, so that it is contained in 5 to 15% by weight. desirable.

Some embodiments of the present invention, 14 parts by weight of ethylene vinyl acetate (EVA), 20 to 55 parts by weight of polyolefin elastomer (POE), 15 to 30 parts by weight of olefin block copolymer (OBC) and styrene-isoprene-styrene스티block copolymer (SIS) 5 to 15 parts by weight, wherein the polyolefin elastomer (POE) is an ethylene-octene copolymer, ethylene-butene copolymer and a thermoplastic elastomer composition for reducing interlayer noise, which is selected from the group consisting of combinations thereof. do.

Meanwhile, the thermoplastic elastomer composition for reducing inter-layer noise according to the present invention may further include ethylene propylene rubber (EPDM). Even when the amount of the crosslinking agent (for example, BIPB) is increased, when a foam is prepared by adding ethylene propylene rubber to the thermoplastic elastomer composition, a stable appearance is formed without poor appearance (for example, bursting of the appearance). can do. More specifically, in the present invention in which ethylene propylene rubber is added, restoring force (or sagging) is improved without a significant change in mechanical strength than a foam made of a thermoplastic elastomer composition to which ethylene propylene rubber is not added. The effect was confirmed.

In particular, considering that the foam is used for the purpose of the interlayer sound insulation material, it is preferable that 5 to 10% by weight of ethylene propylene rubber is included based on the total weight of the thermoplastic elastomer composition. The foam produced therefrom exhibits an effect of improving the resilience (or sagging) and resilience elasticity while stably maintaining the dynamic elasticity. In addition, as described above, ethylene propylene rubber and styrene-isoprene-styrene스티block copolymer (SIS) may be included together in a thermoplastic elastomer composition to improve resilience (sagging property). On the other hand, when the ethylene propylene rubber is contained in an amount of 15% by weight or more based on the total weight of the composition, it exhibits a characteristic that the hardness of the foam produced therefrom is lowered.

Meanwhile, the thermoplastic elastomer composition for reducing inter-layer noise according to the present invention may further include zinc oxide (ZnO). Zinc oxide (ZnO) is a metal oxide and is used to appropriately control the decomposition temperature when a blowing agent having a high decomposition temperature is used together. As the content of zinc oxide (ZnO) in the thermoplastic elastomer composition increases, the specific gravity of the foam produced therefrom gradually decreases. Therefore, it can be seen that zinc oxide (ZnO) functions to promote decomposition of the blowing agent. In addition, compression deformation is improved when zinc oxide (ZnO) is added. That is, zinc oxide (ZnO) can increase the mechanical strength by contributing to the crosslinking efficiency.

The zinc oxide (ZnO) is preferably contained in 1 to 3% by weight based on the total weight of the thermoplastic elastomer composition. When the content was more than 3% by weight, a phenomenon in which compression deformation was lowered was observed.

Meanwhile, the thermoplastic elastomer composition for reducing inter-layer noise according to the present invention may further include zinc stearic acid (Zn-St). Zinc stearate (Zn-St) improves processability by lowering the tack during the compounding process. In addition, the foam made of a thermoplastic elastomer composition containing zinc stearic acid (Zn-St) has improved mechanical strength, and in particular exhibits a cell stabilizing effect of the foam, which is effective in reducing vibration of noise.

As such, zinc stearic acid (Zn-St) is preferably included in 0.5 to 1.3% by weight based on the total weight of the thermoplastic elastomer composition.

Meanwhile, the thermoplastic elastomer composition for reducing noise between layers according to the present invention may further include at least one of a reinforcing agent (or filler), a crosslinking agent, and a blowing agent.

First, the adjuvant in the present invention may include, for example, at least one of talc (Talc) and calcium carbonate (CaCO ₃ ). It is preferable that such a reinforcing agent is contained in 5 to 9% by weight based on the total weight of the thermoplastic elastomer composition. The foam made of a thermoplastic elastomer composition containing a reinforcing agent in the above numerical range does not degrade the dynamic elasticity, but when it is contained in excess of 10% by weight, the elasticity and dynamic elasticity of the foam deteriorate.

Further, as the crosslinking agent of the present invention, a peroxide crosslinking agent having a bis(alpha-t-butyl-peroxyisopropyl)benzene group (BIPB) can be used. Such a peroxide crosslinking agent is, for example, [1,3-phenylenebis(1-methylethylidene)bis[tert-butyl]peroxide{[1,3-Phenylenebis(1-methylethylidene)]bis[tert- butyl]peroxide} and [1,4-phenylenebis(1-methylethylidene)bis[tert-butyl]peroxide{[1,4-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide} It may include at least one of. The crosslinking agent of the present invention is used for imparting viscoelasticity and improving physical properties necessary for the production of a foam from a thermoplastic elastomer composition. In particular, when using a crosslinking agent containing a bis(alpha-t-butyl-peroxyisopropyl)benzene group (BIPB), it is possible to maintain an appropriate stress in the cell of the foam prepared therefrom, and thus the mechanical strength of the foam Improves. In addition, while dicumyl peroxide (DCP) used as a crosslinking agent in the prior art generates harmful substances such as acetophenone or 2-phenyl-2-propanol, the present invention The peroxide crosslinking agent having a bis(alpha-t-butyl-peroxyisopropyl)benzene group (BIPB) is environmentally friendly because it does not generate such harmful substances.

It is preferable that such a crosslinking agent is contained in 0.5 to 0.8% by weight based on the total weight of the thermoplastic elastomer composition. As the content of the crosslinking agent increases, the elasticity of the foam to be produced increases, but when it exceeds 1.2% by weight, physical properties of the foam due to cell stress and poor physical properties (for example, bursting of appearance) occur.

Meanwhile, the foaming agent in the present invention may include, for example, an azodicarbonamide (ADCA) compound. It is preferable that such an azodicarbonamide-based crosslinking agent is contained in 4 to 8% by weight based on the total weight of the thermoplastic elastomer composition.

Subsequently, with reference to FIGS. 1 to 3, the structure and characteristics of the foam for reducing noise between layers manufactured using the thermoplastic elastomer composition according to the present invention will be described.

The thermoplastic elastomer composition of the present invention can be made into a foam through a foaming process after the components are brought into a uniform mixing state. In particular, for the purpose of reducing noise between floors, the foam is molded into a pad or sheet shape to be used as a cushioning material for buildings.

The thermoplastic elastomer composition of the present invention, each of the above-described components, for example, a variety of extruders (extruder), banbari mixer (Banburry mixer), kneader (kneader), continuous kneader (continuous kneader), roll (roll), etc. It can be melt-kneaded by, but is not limited thereto. In addition, the kneading process can be kneaded in various ways, such as kneading by adding each component in batches or by dividing the components.

The thermoplastic resin composition thus produced, injection molding, press molding, calender molding, T die extrusion molding, hollow sheet extrusion molding, foam sheet extrusion molding, inflation molding, lamination molding, vacuum molding, mold release extrusion molding, etc. Molded products can be obtained through various methods of molding such as a combination molding method.

First, referring to FIG. 1, a cross-sectional side view of an interlayer structure in which a foam according to an embodiment of the present invention is installed is illustrated. For example, with a foamable polystyrene foam (expandable polystyrene foam, hereinafter referred to as'EPS foam') 100, a multi-layered cushioning material in which the foam 200 prepared from the thermoplastic elastomer composition according to the present invention is stacked is installed. Can be. Meanwhile, FIG. 1 illustrates that the EPS foam 100 and the foam 200 are stacked and installed side by side, but are not limited thereto.

On the other hand, based on the dynamic elastic modulus of the single structure cushioning material, the dynamic elastic modulus s _'s of the multi-layered cushioning material is calculated from Equation 3 below, assuming that the dynamic modulus when the cushioning material is stacked is a series structure of a continuous spring. Can.

(In the equation 3, _s' s are the same modulus of elasticity of the layered structure, s' _1, s' ₂ and s' is ₃ being the same modulus of elasticity of each single cushion structure).

On the other hand, it is shown that the dynamic elastic modulus coefficient for a multi-layered structure is almost identical when the actual measurement result is compared with the calculated value according to Equation (3). Can.

More specifically, the foam 200 of the present invention may include a highly elastic foam, a general foam, and a shock-absorbing foam in which the above-described constituent components of the thermoplastic resin composition are differently blended according to the purpose.

Referring to FIG. 2, in the interlayer structure in which the foam according to another embodiment of the present invention is installed, together with the EPS foam, two foams 200 and 300 may be positioned side by side. The foams 200 and 300 may have the same composition as each other, or may be foams of the same type (for example, high elastic foams). However, it is possible to have different types of foams (eg, high elastic foam 200 and shock absorbing foam 300) for different purposes.

Meanwhile, in FIG. 2, although the foams 200 and 300 are illustrated to be positioned side by side, the present invention is not limited thereto, and a plurality of foams (for example, three foams) may be installed.

3 is a side cross-sectional view showing an interlayer structure in which a foam is installed according to another embodiment of the present invention. For convenience of description, differences from those described with reference to FIG. 1 will be mainly described.

Referring to FIG. 3, at least one foam 300 may be installed in an uneven shape. That is, for example, as shown in FIG. 3, the uneven foam 300 may be installed under the flat foam 200. As described above, when the flat foam 200 and the uneven foam 300 are used together, the cushioning performance may be further improved.

Hereinafter, the present invention will be described in more detail through examples and comparative examples. However, the following examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

Examples 1 to 4 and Comparative Examples 1 and 2

The thermoplastic elastomer composition according to the present invention, Examples 1 to 4 and Comparative Examples 1 and 2 according to the prior art were blended with the components shown in Table 1 below, and the compositions of Examples 1 to 4 and Comparative Examples 1 and 2 were used. The foam was produced in the form of a pad.

COMPONENT Example 1
(wt%) Example 2
(wt%) Example 3
(wt%) Example 4
(wt%) Comparative Example 1
(wt%) Comparative Example 2
(wt%) EVA 14 10 13 13 47 30 POE 1 17 15 20 15 10 - POE 2 15 25 20 15 - - OBC 15 15 15 25 - - LDPE 15 15 15 15 20 24 SOE - - - - 7 30 SIS 7 7 5 5 - - EPDM 5 5 10 5 - - Zinc oxide (ZnO) 1.2 1.6 1.1 One 1.8 1.8 Zinc stearate (Zn-St) 0.5 0.9 0.9 0.5 0.9 0.9 Adjuvant (Talc) 2 2 - 2 3 3 Adjuvant (CaCO ₃ ) 3.4 3 - 3 4.4 4.4 Crosslinking agent (BIPB(F)) 0.6 0.5 - 0.5 0.6 0.6 Foaming Agent (ADCA) 4.3 - - - 5.3 5.3 total 100 100 100 100 100 100 * EVA: Ethylene Vinyl Acetate
* POE 1: Polyolefin Elastomer-Ethylene Octene Copolymer
* POE 2: Polyolefin Elastomer-Ethylene Butene Copolymer
* OBC: Olefin Block Copolymer
* LDPE: Low Density Polyethylene
* SOE: Hydrogenated Block Copolymer
* SIS: Styrenic TPE
* SBS: PolyStyrene Butadiene Styrene
* EPDM: Ethylene Propylene Diene monomer Rubber
* BIPB (non-toxic crosslinking agent): [1,3(or1,4)-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide
* ADCA: Azodicarbonamide

Measurement of foam properties, dynamic elastic modulus, and changes thereof

The basic dynamic elasticity was measured for the foam in the form of pads prepared using the compositions of Examples 1 to 4 and Comparative Examples 1 and 2, and immediately after heating to 70° C. for 48 hours at room temperature (temperature range of 22 to 26° C.) In the state, the dynamic elasticity of the foam was measured, and the change rate of the dynamic elasticity was measured using the same.

The measured values of dynamic elasticity and the rate of change in dynamic elasticity are shown in Table 2 below.

division UNIT Example 1
(wt%) Example 2
(wt%) Example 3
(wt%) Example 4
(wt%) Comparative Example 1
(wt%) Comparative Example 2
(wt%) Foam
Properties Hardness ASKER C 24 20 27 20 25 25 importance g/cm³ 0.090 0.079 0.088 0.071 0.072 0.077 Shout % 62 65 58 55 45 22 C.set % 50 60 55 70 60 55 Dynamic elasticity
Coefficient Basic dynamic modulus MN/m² 16.3 10.2 17.6 18.6 22.1 52 Dynamic modulus of elasticity after heating
(70℃×48hr) MN/m² 17.5 11.0 19.3 20.5 25.4 66.0 Rate of change after heating % 7.4% 7.8% 9.7% 10.2% 14.9% 26.9%

In Table 2,'basic dynamic modulus of elasticity' refers to the dynamic modulus of foam measured immediately after the manufacture of the foam in the form of a pad, and'dynamic modulus of elasticity after heating (70℃×48hr)' refers to the foam of the pad shape. It means the dynamic modulus of the foam measured at room temperature (temperature range of 22 to 26°C) immediately after heating to 70°C for 48 hours. In addition,'the rate of change after heating' is a value obtained by dividing the difference between the basic dynamic modulus and the basic elastic modulus (70℃×48hr) after heating by the basic dynamic modulus, and heated for 48 hours at 70℃ for the pad-shaped foam. It means the rate of change of the foam dynamic modulus when measured later.

As can be seen from Table 2, in the case of Examples 1 to 4 according to the present invention, the rate of change of the dynamic modulus of elasticity is relatively low from 7.4% to 10.2% even after the time has elapsed, whereas in the case of Comparative Examples 1 and 2 It can be seen that the change in the dynamic elastic modulus according to is significantly increased compared to the example. Accordingly, it can be seen that in the case of the foam produced from the thermoplastic elastomer composition according to the present invention, the dynamic elastic modulus is stably maintained without a sudden change even in an environment in which building temperature conditions (approx. Therefore, even before and after heating, since the coefficient of dynamic elasticity can be continuously maintained for a longer period of time, it is possible to efficiently reduce inter-floor noise generated in buildings such as apartments and apartment houses.

High elastic foam composite, general foam composite, shock absorbing foam composite

The thermoplastic elastomer composition according to the present invention may be used in combination with a conventional expandable polystyrene (EPS) or sponge (Sponge, SP) to produce a multi-layered foamed composite. In particular, high-elastic foam composites (Sample No.: 15-2, 15-3, 15-6, 15-12) by mixing different components within the above-described numerical range according to the purpose of use, general foaming Composites (Sample No.: 15-16), shock-absorbing foam composites (Sample No.: 4-1 190%, and 4-2 210%) are shown in Table 3 below.

In addition, a multi-layered foamed composite (Sample No.: D1) prepared by using a conventional thermoplastic elastomer composition as a control with foam polystyrene (EPS) or sponge (SP) is shown in Table 3 below.

division Control High elasticity Normal Shock absorption Sample number (Serior no.) D1 15-2 15-3 15-6 15-12 15-16 Impulse 4-1
190% Impulse 4-1
210% Properties Hardness (Asker C) 36 17 18 15 15 25 31 25 Specific gravity (g/cm ³ ) 0.072 0.071 0.069 0.066 0.069 0.072 0.104 0.077 C.Set (%) 55 91 91 97 91 79 51 75 Shout (%) 41 64 58 60 62 45 17 23 Dynamic modulus
(MN/m ³ ) Sponge (SP) 13.435 8.022 13.845 11.289 9.161 21.762 90.715 58.736 SP+ Insulation EPS 6.96 5.70 7.25 7.25 5.84 8.18 9.16 9.67 SP+1 EPS 9.67 6.53 8.83 9.85 5.57 14.68 24.98 20.24 Loss
Coefficient Sponge (SP) 0.25 0.176 0.187 0.165 0.220 0.202 0.557 0.449 SP+ Insulation EPS 0.18 0.21 0.22 0.23 0.20 0.24 0.22 0.25 SP+1 EPS 0.17 0.18 0.20 0.16 0.19 0.20 0.34 0.31 Sound insulation rate
(dB) Sponge (SP) plastic ball 111.01 106.22 106.19 106.97 106.46 108.28 115.55 114.04 basketball 95.44 94.19 94.30 94.29 93.23 97.86 90.71 58.74 Insulation EPS plastic ball 105.76 103.79 103.58 104.12 103.95 107.89 110.99 110.17 basketball 93.50 92.51 93.62 93.09 92.53 95.54 96.67 96.57 EPS 1 plastic ball 110.16 105.25 104.76 105.77 104.42 108.67 113.53 111.10 basketball 94.43 93.04 93.90 93.08 93.20 97.46 99.52 99.23

Among the multi-layered foamed composite structures according to the present invention, it can be seen that in the case of the high elastic foamed composite or the general foamed composite, the elasticity and dynamic elastic modulus were significantly increased compared to the control group, and the rest of the physical properties were also improved or at least similar to the control group. In addition, it can be seen that the shock-absorbing foam composite had a higher sound insulation rate than the control group, and the remaining physical properties were also improved or at least similar to the control group. On the other hand, if the same plurality of single structure buffers are used, it is known that the multilayer structure buffers have the same dynamic elastic modulus and noise reduction characteristics regardless of the stacking order of each single structure buffer.

More specifically, referring to the high elastic foam composite (sample number: 15-2, 15-3, 15-6, 15-12) and the general foam composite (sample number: 15-16), the coefficient of dynamic elasticity increases as elasticity increases. Decreases, and accordingly, the noise reduction amount increases (the sound insulation rate increases), so it can be seen that it is more advantageous for noise shielding. In particular, in the case of a high elastic foam composite (Sample No.: 15-2) comprising a sponge (SP) having an elasticity of 64% and a dynamic modulus of 8.022, the noise reduction amount (dB) is lower than that of the control (Sample No.: D1). It can be seen that it is remarkably high.

In conclusion, the foamed composite according to the present invention can be seen through Table 3 that mechanical properties, elasticity, dynamic elasticity, and sound insulation effects are improved compared to the prior art. In addition, as the dynamic elastic modulus of the cushioning material is lower, the noise reduction amount increases, so that the correlation between the dynamic elastic modulus and the interlayer noise reduction can be inferred.

In the above, although the preferred embodiments of the present invention have been illustrated and described, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

100: EPS foam 200, 300: foam

Claims (12)

Ethylene vinyl acetate (EVA) 14 to 30% by weight;
20 to 45% by weight of polyolefin elastomer (POE);
Olefin block copolymer (OBC) 15 to 25% by weight;
15-30% by weight of low density polyethylene (LDPE); And
Styrene-isoprene-styrene block copolymer (SIS) 5 to 7% by weight,
The polyolefin elastomer (POE) is selected from the group consisting of ethylene-octene copolymer, ethylene-butene copolymer and combinations thereof ,
For 100% of the total weight,
10 to 20% by weight of the ethylene-octene copolymer, 10 to 25% by weight of the ethylene-butene copolymer thermoplastic elastomer composition for reducing noise between layers. delete According to claim 1,
The olefin block copolymer (OBC) comprises an ethylene-octene block copolymer,
The ethylene-octene block copolymer,
A thermoplastic elastomer composition for interlayer noise reduction, wherein a hard ethylene-octene block having an octene content of 2.0% by weight and a soft ethylene-octene block having an octene content of 48.3% by weight form a copolymer. According to claim 1,
Ethylene propylene rubber (EPDM) further comprises,
The ethylene propylene rubber (EPDM) is a thermoplastic elastomer composition for reducing interlayer noise contained in 5 to 15% by weight relative to the total weight of the thermoplastic elastomer composition. According to claim 1,
Further comprising zinc oxide (ZnO),
The zinc oxide (ZnO) is a thermoplastic elastomer composition for reducing interlayer noise contained in 1 to 3% by weight relative to the total weight of the thermoplastic elastomer composition. According to claim 1,
Zinc stearic acid (Zn-St) further comprises,
The zinc stearic acid (Zn-St) is a thermoplastic elastomer composition for reducing interlayer noise contained in 0.5 to 1.3% by weight relative to the total weight of the thermoplastic elastomer composition. According to claim 1,
A thermoplastic elastomer composition for reducing noise between layers further comprising at least one of a reinforcing agent, a crosslinking agent, and a blowing agent. The method of claim 7,
The adjuvant,
A thermoplastic elastomer composition for reducing interlayer noise comprising at least one of talc and calcium carbonate (CaCO ₃ ). The method of claim 7,
The crosslinking agent,
Thermoplastic for noise reduction between layers comprising at least one of [1,3-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide and [1,4-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide Elastomer composition. The method of claim 7,
The foaming agent, a thermoplastic elastomer composition for reducing interlayer noise comprising an azodicarbonamide compound. A foam for reducing interlayer noise produced by using the thermoplastic elastomer composition according to any one of claims 1 and 3 to 10. The method of claim 11,
The foam is an interlayer noise reduction foam having an uneven shape.

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