TW202229433A - Ethylene vinyl acetate composite resin composition having excellent melt elasticity and uses of the same - Google Patents

Abstract

Provided is an ethylene vinyl acetate-elastomer composite resin composition including a highly expandable ethylene vinyl acetate copolymer resin. More particularly, an ethylene vinyl acetate-elastomer composite resin composition having an expansion rate of 80% or more using melt elasticity control is provided.

Description

Ethylene vinyl acetate composite resin composition with excellent melt elasticity and its application

The following disclosure relates to an ethylene vinyl acetate-elastomer composite resin composition comprising a highly expandable ethylene vinyl acetate copolymer resin. More specifically, the following disclosure relates to an ethylene vinyl acetate-elastomer composite resin composition, which utilizes melt elasticity control to use ethylene vinyl acetate having an expansion ratio of 80% or more and has 50% or more of 50% or more. % expansion rate.

In recent years, as interest in high-performance footwear that is light in weight, has excellent elasticity, and has various functions such as low hardness and compression deformation has increased, there is a need to develop high-performance running shoes and the like that use a composite material instead of a single material.

Specifically, ethylene vinyl acetate copolymer (EVA), as the most representative sports shoe cushioning material responsible for the core part of the sports shoe function, is easy to process at low temperature, easy to crosslink and form The foam is excellent in terms of foam cells, and thus has been stably developed as a functional sports shoe material.

In addition, the use of composite materials in which ethylene vinyl acetate copolymers and thermoplastic elastomers are mixed is increasing, and furthermore, various thermoplastic elastomers having high melting points have recently been used to develop composite materials in accordance with the recent trend to require low specific gravity properties.

The composite material using thermoplastic elastomer has the advantages of both ethylene vinyl acetate copolymer and thermoplastic elastomer, and shows better physical properties, but in fact, when these two materials are simply mixed, it is difficult to meet the expected physical properties. nature.

In order to obtain the effect of sufficiently improving the physical properties of the thermoplastic elastomer composite, the expansion ratio of the foam or the expansion ratio in a thermal process such as foaming should be high, but the usual ethylene vinyl acetate copolymer resin does not show sufficient expansion properties.

In addition, thermoplastic elastomers used with conventional ethylene vinyl acetate copolymers have low melt elasticity, therefore, the two-component blended composites do not exhibit sufficient foaming properties during the expansion process or during the foaming process, Or even if it exhibits foaming properties, it is difficult to have a uniform cell structure, so there is a limitation in use.

In addition, it was found that when processing with conventional ethylene vinyl acetate copolymers with resins having a high melting point (eg thermoplastic elastomers), the processability was significantly lower and the foams produced were difficult to satisfy eg sufficient elasticity and physical properties such as mechanical strength.

In order to solve these problems, many studies have been carried out and it has been found that in order to have an independent and uniform cell structure in the foaming process, the expansion rate of the composite material itself (the composite material itself without the addition of a foaming agent) should be 50% or more than 50%, preferably 80% or more, so that the material can have a uniform cell structure in the foaming process and ensure the desired physical properties, and thus complete the present invention.

That is, it was found that when resins having a high melting point (eg, thermoplastic elastomers) were processed with conventional ethylene vinyl acetate copolymers, the processability became significantly lower, thus making processing difficult and defective in footwear manufacturing equipment The rate increases, and it is difficult for the produced foam to satisfy physical properties such as sufficient elasticity and mechanical strength.

[Related technical literature]

[Patent Literature] (Patent Document 1) Korean Patent Early Publication No. 10-2018-0045466 (May 4, 2018)

[technical problem]

One aspect of the present invention aims to provide a highly expandable ethylene vinyl acetate composite resin composition, which improves the melt elasticity and expansion ratio of ethylene vinyl acetate, so as to have a high expansion ratio and be suitable for use as high-performance running shoes Physical properties of materials.

Another aspect of the present invention aims to provide an ethylene vinyl acetate-elastomer composite resin composition having a high expansion ratio and forming a uniform foam cell structure.

Another aspect of the present invention aims to provide an ethylene vinyl acetate-elastomer composite resin composition, which can have significantly improved processability when processed with resins having high melting points such as thermoplastic elastomers .

Still another embodiment of the present invention aims to provide a highly expandable ethylene vinyl acetate-copolymer resin, which has excellent foamability and elasticity, and can provide a foam with a smooth surface.

[Problem solution]

In a general solution, the ethylene vinyl acetate-elastomer composite resin composition with an expansion ratio of 50% or more includes: a highly expandable ethylene vinyl acetate copolymer with an expansion ratio of 80% or more resin and a thermoplastic elastomer.

According to an exemplary embodiment of the present invention, the composite resin composition may include 1 part by weight to 100 parts by weight of the thermoplastic elastomer.

According to an exemplary embodiment of the present invention, the highly expandable ethylene vinyl acetate copolymer resin may have an expansion ratio of 100% or greater.

According to an exemplary embodiment of the present invention, the highly expandable ethylene vinyl acetate copolymer resin may have an expansion ratio of 130% or greater.

According to an exemplary embodiment of the present invention, the ethylene vinyl acetate-elastomer composite resin composition may have an expansion ratio of 50% or more.

According to an exemplary embodiment of the present invention, the ethylene vinyl acetate-elastomer composite resin composition may have an expansion ratio of 80% or more.

According to an exemplary embodiment of the present invention, the highly expandable ethylene vinyl acetate copolymer resin may comprise cross-linking by using any one selected from the group consisting of thermal cross-linking, radiation cross-linking, X-ray cross-linking and electron beam cross-linking. A resin produced by modifying ethylene vinyl acetate copolymer resin by a method.

According to an exemplary embodiment of the present invention, the thermoplastic elastomer may include an elastomer capable of radical modification.

According to an exemplary embodiment of the present invention, the thermoplastic elastomer may include a resin selected from the group consisting of styrene-butadiene-styrene resin, styrene-isobutylene-styrene resin, styrene-ethylene-butylene-styrene resin , styrene-ethylene-propylene-styrene resin, styrene-isoprene-styrene resin, isoprene rubber, butadiene rubber, chloroprene rubber, ethylene-propylene rubber, ethylene-propylene- Any one or two or more of diene rubber, thermoplastic polyolefin elastomer, thermoplastic polyester elastomer, thermoplastic polyamide elastomer, and thermoplastic polyurethane.

In another general aspect, an ethylene vinyl acetate-elastomer composite resin foam produced by foaming the ethylene vinyl acetate-elastomer composite resin composition, the ethylene vinyl acetate-elastomer The bulk composite resin composition further includes a crosslinking agent, a foaming agent and inorganic particles.

According to an exemplary embodiment of the present invention, the ethylene vinyl acetate-elastomer composite resin foam may include 0.1 parts by weight to 3 parts by weight based on 100 parts by weight of the ethylene vinyl acetate-elastomer composite resin composition parts by weight of the cross-linking agent, 1 to 20 parts by weight of the foaming agent, and 0.1 to 20 parts by weight of the inorganic particles.

According to an exemplary embodiment of the present invention, the cross-linking agent may include a compound selected from the group consisting of bis(tertiary butyl) peroxide, bis(tertiary pentyl) peroxide, tertiary butyl cumyl peroxide oxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tertiarybutylperoxy)hexane, 3,2,2'-bis(tertiarybutylperoxy)hexane Oxyisopropyl)benzene, 1,1-bis(tertiarybutylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tertiarybutylperoxy) ) valerate, benzyl peroxide, p-chlorobenzyl peroxide, tertiary butyl peroxybenzoate and 2,5-dimethyl-2,5-bis(tertiary benzyl peroxide) Either or a mixture of hexanes.

According to an exemplary embodiment of the present invention, the blowing agent may include a foaming agent selected from the group consisting of azo[di]formamide, azobisisobutyronitrile, diazoamine azobenzene, N,N'-diimide Any of nitropentamethylenetetramine, p-toluenesulfohydrazine, p,p'-oxybis(benzenesulfonylhydrazine), p-toluenesulfonamide urea, sodium bicarbonate or its a mixture.

According to an exemplary embodiment of the present invention, the inorganic particles may include any one or a mixture of two or more selected from calcium carbonate, zinc oxide, calcium oxide, magnesium oxide, silicon oxide, aluminum oxide, and titanium dioxide .

[Beneficial effects of the invention]

The ethylene vinyl acetate-elastomer composite resin composition according to the present invention has a high expansion ratio and can form a uniform foam cell structure.

That is, the ethylene vinyl acetate-elastomer composite resin composition itself according to the present invention can provide an expansion ratio of 50% or more, more specifically 80% or more (in the absence of a blowing agent). state) composition.

In addition, the ethylene vinyl acetate-elastomer composite resin composition according to the present invention has excellent foamability and exhibits excellent processability, whereby it can be applied to various devices.

In addition, the foam according to the present invention has excellent flexibility, elasticity and durability, and also has a smooth surface without defects.

In the following, the present invention will be described in more detail with reference to specific examples and exemplary implementations. However, the following specific examples or exemplary implementation aspects are only for reference to describe the present invention in detail, and the present invention is not limited thereto and can be implemented in various forms.

Also, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by those skilled in the art to which this invention belongs. The terms used herein are used only to effectively describe a particular embodiment and are not intended to limit the invention.

Furthermore, use of the singular in the specification and the appended claims may be intended to include the plural as well, unless the context dictates otherwise.

Furthermore, unless specifically described to the contrary, "comprising, including" any element will be understood to imply the further inclusion of other elements, but not the exclusion of any other elements.

In the present invention, the "expansion rate" refers to the expansion rate of the resin or composite resin composition alone in a state in which no foaming agent is contained.

In this specification, "modification" means to perform cross-linking chemically or physically (eg, by ultraviolet rays, radiation, etc.).

The present invention relates to an ethylene vinyl acetate-elastomer composite resin composition, which is composed of an ethylene vinyl acetate with an expansion ratio of 80% and an ethylene vinyl acetate-elastomer composite resin with a thermoplastic elastomer thing.

According to an exemplary embodiment of the present invention, based on 100 parts by weight of the highly expandable ethylene vinyl acetate copolymer resin having an expansion ratio of 80% or more, the composite resin composition may include 1 part by weight to 100 parts by weight. parts by weight of thermoplastic elastomer.

As an example, the ethylene vinyl acetate-elastomer composite resin composition of the present invention includes an ethylene vinyl acetate copolymer resin and a thermoplastic elastomer, the expansion ratio of which is 50% or more, and is obtained by using 100 parts by weight of the highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 80% or more is produced by including 1 part by weight to 100 parts by weight of the thermoplastic elastomer.

As an exemplary embodiment, the ethylene vinyl acetate-elastomer composite resin composition of the present invention includes the thermoplastic elastomer and the highly expandable ethylene vinyl acetate copolymer resin, the expansion ratio of which is 50 under these conditions % or more, thereby providing an ethylene vinyl acetate-elastomer composite resin composition that solves the problem of low uniformity of the foam cell structure that usually occurs when the two resins are used together, and It has remarkably excellent foamability and elasticity, so it is more preferable.

In addition, the inventors of the present invention have studied the closed uniform cell structure in the foaming process such as in functional footwear, and found that by using a highly expandable ethylene vinyl acetate with an expansion ratio of 80% or more An ester copolymer resin, which can form a uniform cell structure and can ensure desired physical properties, has completed the present invention.

In an exemplary embodiment of the present invention, the highly expandable ethylene vinyl acetate copolymer resin may have 100% or more, preferably 130% or more, and more preferably 180% or more 180% expansion rate.

In an exemplary embodiment of the present invention, the ethylene vinyl acetate-elastomer composite resin composition may have 50% or more, preferably 80% or more, and more preferably 150% or Expansion rate greater than 150%.

The content of vinyl acetate in the ethylene vinyl acetate may be 10% to 60%, preferably 15% to 50%, and more preferably 20% to 40%, but not limited thereto. Furthermore, in the present invention, ethylene vinyl acetate may have a range of 0.1 g/10 minutes (g/10 min) to 8.0 g/10 min, preferably 0.2 g/10 min to 6.0 g/10 min, and more preferably Melt index (190°C, 2.16 kg) of 0.3 g/10min to 4.0 g/10min, but not limited thereto.

When the highly expandable ethylene vinyl acetate copolymer resin has a melt index and a vinyl acetate content within the above ranges and has an expansion ratio within the above ranges, ethylene vinyl acetate having remarkably excellent foamability and elasticity can be achieved Ester-elastomer composite resin composition.

Specifically, by producing an ethylene vinyl acetate-elastomer composite resin composition in which the highly expandable ethylene vinyl acetate copolymer resin satisfies the expansion ratio range, the mechanical and chemical properties between the components are well combined to further improve melt elasticity. In addition, by using the ethylene vinyl acetate-elastomer composite resin composition, a foam having an extremely uniform cell structure can be formed.

Compared with the traditional production of composite materials based on ethylene vinyl acetate copolymers using thermoplastic elastomers, it is difficult to produce high-quality foams due to the low foamability of thermoplastic elastomers themselves. The ethylene vinyl acetate-elastomer composite resin composition of ethylene vinyl acetate copolymer exhibits excellent foamability even when a high content of thermoplastic elastomer is used together, and the produced foam is soft and smooth And the surface without defect problem.

A thermoplastic elastomer system according to an exemplary embodiment of the present invention is mixed with a highly expandable ethylene vinyl acetate resin to improve the elasticity and reduce the hardness and compression set of the ethylene vinyl acetate-elastomer composite resin composition, thereby producing A highly functional composite material. Specifically, for example, it may be selected from the group consisting of styrene-butadiene-styrene (SBS), styrene-isobutylene-styrene (SIBS), styrene-ethylene-butylene-styrene (SEBS), benzene Ethylene-ethylene-propylene-styrene (SEPS), styrene-isoprene-styrene (SIS), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR) ), ethylene propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), thermoplastic polyolefin elastomer (POE), thermoplastic polyester elastomer (TPEE), thermoplastic polyamide elastomer (TPA), thermoplastic polyurethane (TPU) etc. or a mixture of two or more.

As an exemplary embodiment, preferably based on 100 parts by weight of the highly expandable ethylene vinyl acetate copolymer resin, the ethylene vinyl acetate-elastomer composite resin composition comprises 1 part by weight to 100 parts by weight, a relatively Preferably, 10 to 50 parts by weight of the thermoplastic elastomer is used to obtain a composition with an expansion ratio of 50% or more, but the present invention is not limited thereto.

In an exemplary embodiment of the present invention, in the highly expandable ethylene vinyl acetate copolymer resin composition, the highly expandable ethylene vinyl acetate copolymer resin can be cross-linked by thermal cross-linking, radiation cross-linking , X-ray cross-linking, electron beam cross-linking, etc. to modify the ethylene vinyl acetate copolymer resin to produce, but not limited to this, as long as it is to achieve 80% or more than 80% expansion rate means.

Specifically, although the present invention is characterized by the use of a highly expandable ethylene vinyl acetate copolymer resin adjusted to have an expansion ratio of 80% or more by the above-described cross-linking method, when the cross-linking method is not used In this case, when a highly expandable ethylene vinyl acetate copolymer resin having an expansion ratio of 80% or more is used, the same effect as that obtained by using a crosslinked highly expandable ethylene vinyl acetate copolymer resin can be exhibited. .

The expansion ratio of the highly expandable ethylene vinyl acetate copolymer resin may have a strand expansion ratio of 80% or more, preferably 100% or more, and more preferably 130% or more , the strand was melted in a melt indexer at 190°C and 2.16 kg and passed through a hole with a diameter of 2.096 mm.

In general, when ethylene vinyl acetate copolymer is foamed with other thermoplastic elastomers to produce a composite material, the thermoplastic elastomer has low melt elasticity, resulting in difficult foaming and increased defect rate.

However, the ethylene vinyl acetate-elastomer composite resin composition of the present invention basically includes a highly expandable ethylene vinyl acetate copolymer resin having an expansion ratio within the above-mentioned range, thereby exhibiting improved melt elasticity. Therefore, the uniform foaming effect is excellent, and a foam having a smooth surface and excellent appearance can be produced, so the composition can be easily applied as a composite material to various fields including high-performance footwear.

The thermoplastic elastomer may be an elastomer capable of free-radical crosslinking selected from the group consisting of styrene-butadiene-styrene (SBS), styrene-isobutylene-styrene (SIBS), styrene-ethylene- Butene-styrene (SEBS), styrene-ethylene-propylene-styrene (SEPS), styrene-isoprene-styrene (SIS), isoprene rubber (IR), butadiene rubber ( BR), chloroprene rubber (CR), ethylene propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), thermoplastic polyolefin elastomer (POE), thermoplastic polyester elastomer (TPEE), thermoplastic polyolefin Amide elastomer (TPA), thermoplastic polyurethane (TPU), etc.

In addition, the present invention relates to an ethylene vinyl acetate-elastomer composite resin foam comprising a foam comprising a foaming agent and a crosslinking agent in an ethylene vinyl acetate-elastomer composite resin composition The ethylene vinyl acetate-elastomer composite resin composition is produced by comprising a strand of highly expandable ethylene vinyl acetate copolymer resin having a stock expansion ratio of 80% or more and a thermoplastic elastomer, The strands were melted in a melt indexer at 190°C and 2.16 kg and passed through a 2.096 mm diameter hole.

In addition, an ethylene vinyl acetate-elastomer composite resin foam can be provided which is foamed by an ethylene vinyl acetate-elastomer composite resin composition further comprising a crosslinking agent, a foaming agent and inorganic particles and production. More specifically, the ethylene vinyl acetate-elastomer composite resin foam can be provided by foaming the ethylene vinyl acetate-elastomer composite resin, consisting of 100 parts by weight of the ethylene vinyl acetate-elastomer composite resin In terms of material, the ethylene vinyl acetate-elastomer composite resin includes 0.1 to 3 parts by weight of a crosslinking agent, 1 to 20 parts by weight of a foaming agent, and 0.1 to 20 parts by weight of inorganic particles.

Ethylene vinyl acetate-elastomer composite resin foam is easy to foam, and there are no problems such as premature foaming, difficulty in forming open cells, and cell collapse during the foaming process, and the produced foam has a flexible Non-hard, smooth and glossy surface and excellent physical properties.

A blowing agent, a crosslinking agent, and inorganic particles may be further included in the ethylene vinyl acetate-elastomer composite resin composition to produce an ethylene vinyl acetate-elastomer composite resin foam.

As a foaming agent, azo[di]formamide, azobisisobutyronitrile, diazoaminoazobenzene, N,N'-dinitrosopentamethylenetetramine, p-toluenesulfonic acid can be used Hydrazine, p,p'-(oxybisbenzenesulfohydrazine), p-toluenesulfonamide, sodium bicarbonate, etc., but the present invention is not limited thereto.

Preferably, based on 100 parts by weight of the ethylene vinyl acetate-elastomer composite resin composition, any one or a mixture of two or more of the foaming compounds may be 1 to 20 parts by weight, specifically Said amount of 2 to 16 parts by weight, and more specifically 3 to 10 parts by weight is used, but not limited thereto. When the ethylene vinyl acetate-elastomer composite resin composition is foamed using the azo compound within the above content range, the foaming agent stably forms the cell structure of the foam while forming uniform dispersion, and the desired The foaming ratio and mechanical properties are required, so it is effective.

In addition, a cross-linking agent may be added to further improve the melt elasticity of the ethylene vinyl acetate-elastomer composite resin composition upon foaming, and specifically, a compound selected from the group consisting of di(tertiary butyl) peroxide, di(tertiary butyl) peroxide, (tertiary amyl) peroxide, tertiary butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tertiary butyl peroxide) oxy) hexane, 3,2,2'-bis(tertiarybutylperoxyisopropyl)benzene, 1,1-bis(tertiarybutylperoxy)-3,3,5-trimethyl ring Hexane, n-butyl-4,4-bis(tertiary butylperoxy)valerate, benzyl peroxide, p-chlorobenzyl peroxide, tertiary butyl peroxybenzoate and 2,5 - any one or a mixture of dimethyl-2,5-bis(tertiary benzyl peroxy)hexane, but the present invention is not limited thereto. Based on 100 parts by weight of the ethylene vinyl acetate-elastomer composite resin composition, the content of the crosslinking agent may be 0.1 parts by weight to 3 parts by weight, specifically 0.2 parts by weight to 2 parts by weight, and more specifically It is 0.5 to 1 part by weight, but not limited thereto. When the crosslinking agent is used within the above range, the ethylene vinyl acetate-elastomer composite resin composition can have sufficient viscoelasticity to withstand the gas pressure generated by the decomposition of the blowing agent during the foaming process.

In addition, the inorganic particles may specifically be, for example, any one or a mixture of two or more selected from calcium carbonate, zinc oxide, calcium oxide, magnesium oxide, silicon oxide, aluminum oxide, and titanium dioxide. Preferably, the use of a mixture of calcium carbonate and titanium dioxide can promote cross-linking and foaming when generating the foam, but the present invention is not limited thereto. Based on 100 parts by weight of the ethylene vinyl acetate-elastomer composite resin composition, the content of the inorganic particles may be 0.1 part by weight to 20 parts by weight, specifically 1 part by weight to 18 parts by weight, and more specifically 4 to 15 parts by weight, but not limited thereto.

The ethylene vinyl acetate-elastomer composite resin composition includes a thermoplastic elastomer having an expansion ratio of less than 50%, but exhibits a high expansion ratio within the aforementioned range, and thus can form a uniform foam cell structure upon foaming , and has an excellent effect of stably producing foam without defects due to open cells, cell collapse, etc.

Furthermore, when a foam is produced using the ethylene vinyl acetate-elastomer composite resin composition, desired physical properties such as elasticity, flexibility, hardness and durability can be easily achieved, and the produced foam Has a smoother surface and shows excellent gloss.

In addition, the foam composition may further include a dispersant, a viscosity modifier, a colorant, an antioxidant, an ultraviolet stabilizer, an anti-caking agent, etc., within a range that does not impair the purpose of the present invention, but is not limited thereto.

The blowing agent according to an exemplary embodiment of the present invention can be produced by known foam molding methods such as injection foaming. Specifically, for example, the ethylene vinyl acetate-elastomer composite resin composition is softened using a known kneader, a roll mill, or the like, and then a crosslinking agent, a foaming agent, and inorganic particles are added thereto to produce ethylene vinyl acetate Ester-elastomer composite resin foam composition, which was softened using an extruder to form pellets.

introducing this into a foam injection machine to inject the ethylene vinyl acetate-elastomer composite resin foam composition into a mold designed to be reduced at a rate relative to the foam volume, and The mold is then pressed, heated and disassembled to produce a foam.

Here, the mixing and softening may be performed at a temperature of 50°C to 250°C, and the injection of the ethylene vinyl acetate-elastomer composite resin foam composition may be performed at less than 120°C, specifically less than 100°C, and more specifically Specifically, it is performed at a temperature of 70°C to 100°C, and the temperature of the mold may be 100°C to 250°C, specifically 140°C to 200°C, and more specifically 160°C to 180°C, but the present invention It is not limited to this.

The foaming ratio may be 120% to 200%, specifically 150% to 180%, but not limited thereto.

The foam of the present invention is produced by mixing a strand of highly expandable ethylene vinyl acetate copolymer resin having an expansion ratio of 80% or more with a thermoplastic elastomer and foaming the strand at 190° C. and It melts in a melt index meter under the condition of 2.16 kg, and passes through a hole with a diameter of 2.096 mm, and thus exhibits excellent properties such as light weight, flexibility, elasticity, hardness and physical properties such as compression deformation, and also has significantly improved surface properties.

Specifically, the foam is easy to foam without the problems of conventional composite materials including ethylene vinyl acetate copolymer and thermoplastic elastomer in the foaming process, specifically, premature foaming, difficulty in forming The open cells or cells collapse, and the foam produced has a soft but not hard, smooth and glossy surface and excellent physical properties.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples and comparative examples are merely examples for describing the present invention in more detail, and do not limit the present invention in any way.

(Evaluate)

1. Foam moldability

The foam cells of a foam were observed with the naked eye, and when the size and uniformity of the foam cells were excellent, it was represented by ◎, and when the size and uniformity were good, it was represented by ○ , when the size of the cells of the foam is large and the uniformity is low, it is expressed as Δ, and when premature foaming occurs or cell formation is difficult, it is expressed as X.

2. Appearance

The appearance of the foam was confirmed with the naked eye, and when the surface was rough or wrinkled, it was expressed as "bad", when there was no appearance defect and the surface gloss was poor, it was expressed as "good", and when the surface gloss was excellent and When there is no appearance defect, it is expressed as "Excellent".

3. Hardness

The hardness of the foam was measured by using an Asker C-type durometer, which was pressed against the surface of the foam, and the hardness was measured after 1 to 2 seconds.

4. Resilience

The resilience of the foam was measured using a resilience meter as the average of 4 to 6 measurements after 1 to 3 ball drops.

5. Permanent compression reduction rate

The permanent compression reduction of the foam was measured by compressing a 10 mm sample to 5 mm, storing the sample at 50°C/6 hours, allowing the sample to stand at room temperature for 30 hrs. minutes, and the recovery height is calculated by the following equation 1: [Equation 1]

6. Expansion rate

其中A為穿過孔管之線料之直徑，且B為孔管之直徑。 The expansion ratio of the strand melted at 190°C and 2.16 kg in a melt index meter and passed through a hole with a diameter of 2.096 mm was calculated by the following Mathematical formula 1: [Mathematical formula 1]

where A is the diameter of the wire passing through the hole tube, and B is the diameter of the hole tube.

[Example 1]

Based on 100 parts by weight of a highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 80%, 40 parts by weight of a thermoplastic polyester elastomer (TPEE, SK Chemical, G140D) was introduced at 180°C to a diameter of 27 The mixing was carried out in a twin screw extruder of 300 mm in size and at a screw speed of 300 revolutions per minute (rpm) to produce an ethylene vinyl acetate-elastomer composite resin composition. The expansion ratios of the produced composite resin compositions are shown in Table 1.

Based on 100 parts by weight of the produced ethylene vinyl acetate-elastomer composite resin composition, 0.8 parts by weight of dicumyl peroxide (Perkadox BC-FF, Akzonobel), 7 parts by weight of azo[ Di]formamide (JTR-TL, Kumyang), 4 parts by weight of calcium carbonate (B50 CaCO ₃ , Buwon) and 8 parts by weight of titanium dioxide (B50 TiO ₂ , Buwon) were introduced into a roll mill, mixing was performed, And the extrusion was performed in a single screw extruder, and the extrudate was cut to produce the foam composition in the form of a pellet. When the foam cells were observed after the composition was foamed, the foam cell uniformity, appearance and physical properties of the produced foam compositions were confirmed and shown in Table 2.

[Example 2]

Except for using 60 parts by weight of TPEE (SK Chemical, G140D) with respect to 100 parts by weight of a highly expandable ethylene vinyl acetate copolymer resin having an expansion ratio of 80% to produce a monoethylene vinyl acetate-elastomer composite resin composition, And in the same manner as in Example 1 except that 6.5 parts by weight of azo[di]formamide (JTR-TL, Kumyang) was used in 100 parts by weight of ethylene vinyl acetate-elastomer composite resin composition The process is performed. The physical properties are shown in Table 2 below.

[Example 3]

100 parts by weight of TPEE (SK Chemical, G140D) was used in addition to 100 parts by weight of a highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 80% to produce a monoethylene vinyl acetate-elastomer composite resin composition , and in addition to using 6 parts by weight of azo[di]formamide (JTR-TL, Kumyang) in 100 parts by weight of ethylene vinyl acetate-elastomer composite resin composition, in the same manner as in Example 1 way to execute the process. The physical properties are shown in Table 2 below.

[Example 4]

In addition to using 40 parts by weight of TPEE (SK Chemical, G140D) based on 100 parts by weight of a highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 100% to produce a monoethylene vinyl acetate-elastomer composite resin composition, And in the same manner as in Example 1, except that 7.5 parts by weight of azo[di]formamide (JTR-TL, Kumyang) was used in 100 parts by weight of ethylene vinyl acetate-elastomer composite resin composition The process is executed. The physical properties are shown in Table 2 below.

[Example 5]

Except using 40 parts by weight of TPEE (SK Chemicals, G140D) based on 100 parts by weight of a highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 130% to produce a monoethylene vinyl acetate-elastomer composite resin composition, And in the same manner as in Example 1 except that 8 parts by weight of azo[di]formamide (JTR-TL, Kumyang) was used in 100 parts by weight of ethylene vinyl acetate-elastomer composite resin composition The process is performed. The physical properties are shown in Table 2 below.

[Comparative Example 1]

In addition to using 40 parts by weight of TPEE (SK Chemical, G140D) based on 100 parts by weight of a highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 50% to produce a monoethylene vinyl acetate-elastomer composite resin composition, And in the same manner as in Example 1 except that 5 parts by weight of azo[di]formamide (JTR-TL, Kumyang) was used in 100 parts by weight of ethylene vinyl acetate-elastomer composite resin composition The process is executed. The physical properties are shown in Table 2 below.

[Comparative Example 2]

Except using 40 parts by weight of TPEE (SK Chemical, G140D) based on 100 parts by weight of the expandable ethylene vinyl acetate copolymer resin having an expansion ratio of 30% to produce a monoethylene vinyl acetate-elastomer composite resin composition, and It was carried out in the same manner as in Example 1 except that 4.5 parts by weight of azo[di]formamide (JTR-TL, Kumyang) was used in 100 parts by weight of ethylene vinyl acetate-elastomer composite resin composition this process. The physical properties are shown in Table 2 below.

[Table 1] EVA expansion rate (%) EVA content (parts by weight) TPEE content (parts by weight) Expansion ratio of ethylene vinyl acetate composite resin composition (%) Example 1 80 100 40 59 Example 2 80 100 60 51 Example 3 80 100 100 43 Example 4 100 100 40 73 Example 5 130 100 40 93 Comparative Example 1 50 100 40 36 Comparative Example 2 30 100 40 twenty one

[Table 2] foam plasticity Exterior Foaming ratio (%) Hardness (Asker C) Resilience (%) Permanent compression reduction rate (%) Example 1 ◎ excellent 160 47 60 53 Example 2 ◎ excellent 160 50 57 55 Example 3 ○ good 160 51 54 54 Example 4 ◎ excellent 160 48 60 51 Example 5 ◎ excellent 160 48 62 47 Comparative Example 1 △ bad 160 42 48 66 Comparative Example 2 X bad 160 41 46 68

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:none.

Claims (13)

An ethylene vinyl acetate-elastomer composite resin composition comprises: a highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 80% or more and a thermoplastic elastomer. The ethylene vinyl acetate-elastomer composite resin composition according to claim 1, wherein based on 100 parts by weight of the highly expandable ethylene vinyl acetate copolymer resin with an expansion ratio of 80% or more, it comprises 1 to 100 parts by weight of the thermoplastic elastomer. The ethylene vinyl acetate-elastomer composite resin composition of claim 1, wherein the highly expandable ethylene vinyl acetate copolymer resin has an expansion ratio of 100% or more. The ethylene vinyl acetate-elastomer composite resin composition of claim 1, wherein the highly expandable ethylene vinyl acetate copolymer resin has an expansion ratio of 130% or more. The ethylene vinyl acetate-elastomer composite resin composition according to claim 1, wherein the ethylene vinyl acetate-elastomer composite resin composition has an expansion ratio of 80% or more. The ethylene vinyl acetate-elastomer composite resin composition as claimed in claim 1, wherein the highly expandable ethylene vinyl acetate copolymer resin is cross-linked by heat cross-linking, radiation cross-linking, X-ray cross-linking It is produced by modifying ethylene vinyl acetate copolymer resin by any method of electron beam crosslinking. The ethylene vinyl acetate-elastomer composite resin composition according to claim 1, wherein the thermoplastic elastomer can undergo radical modification. The ethylene vinyl acetate-elastomer composite resin composition according to claim 7, wherein the thermoplastic elastomer is selected from the group consisting of styrene-butadiene-styrene resin, styrene-isobutylene-styrene resin, styrene- Ethylene-butylene-styrene resin, styrene-ethylene-propylene-styrene resin, styrene-isoprene-styrene resin, isoprene rubber, butadiene rubber, chloroprene rubber, ethylene - Any one or a mixture of two or more of propylene rubber, ethylene-propylene-diene rubber, thermoplastic polyolefin elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers and thermoplastic polyurethanes. An ethylene vinyl acetate-elastomer composite resin foam produced by foaming the ethylene vinyl acetate-elastomer composite resin composition as described in any one of claims 1 to 8, the ethylene vinyl acetate-elastomer composite resin composition being foamed The vinyl acetate-elastomer composite resin composition further includes a crosslinking agent, a foaming agent, and inorganic particles. The ethylene vinyl acetate-elastomer composite resin foam as claimed in claim 9, wherein the ethylene vinyl acetate-elastomer composite resin foaming system is compounded by 100 parts by weight of the ethylene vinyl acetate-elastomer The resin composition is produced by including 0.1 to 3 parts by weight of the crosslinking agent, 1 to 20 parts by weight of the foaming agent and 0.1 to 20 parts by weight of the inorganic particles. The ethylene vinyl acetate-elastomer composite resin foam according to claim 9, wherein the crosslinking agent is selected from the group consisting of di(tertiary butyl) peroxide and di(tertiary pentyl) peroxide , tertiary butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tertiary butylperoxy) hexane, 3,2, 2'-bis(tertiary butylperoxyisopropyl)benzene, 1,1-bis(tertiary butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4, 4-Bis(tertiary butylperoxy)valerate, benzyl peroxide, p-chlorobenzyl peroxide, tertiary butyl peroxybenzoate and 2,5-dimethyl-2,5- Either or a mixture of bis(tertiary benzyl peroxy)hexane. The ethylene vinyl acetate-elastomer composite resin foam according to claim 9, wherein the blowing agent is selected from azo[di]formamide, azobisisobutyronitrile, and diazoamine azo Nitrobenzene, N,N'-dinitrosopentamethylenetetramine, p-toluenesulfohydrazine, p,p'-oxybis(benzenesulfonylhydrazine), p-toluenesulfonamide urea and sodium bicarbonate ( sodium bicarbonate) or a mixture thereof. The ethylene vinyl acetate-elastomer composite resin foam according to claim 9, wherein the inorganic particles are any one selected from calcium carbonate, zinc oxide, calcium oxide, magnesium oxide, silicon oxide, aluminum oxide and titanium dioxide A mixture of one or two or more.