TWI780526B - High-functional foaming resin composition and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a resin composition for high-function foaming and a preparation method thereof, in particular, relates to the ability to provide high-profile foaming materials such as insoles, midsoles, and outsoles, etc. A high-function foaming resin composition with split tear strength and high resilience and a preparation method thereof.

Description

Resin composition for high-function foaming and preparation method thereof

The present invention relates to a high-function foaming resin composition and a preparation method thereof, in particular to the ability to provide high-profile foams when manufacturing shoe-making materials, such as insoles, midsoles, and outsoles. Resin composition for high function foaming with split tear strength and high resilience and its preparation method.

Polymer foam refers to a dual-state object in which air bubbles coexist in solid polymers. It is widely used in various applications such as water-absorbing materials, cushioning materials, heat-insulating materials, sound-absorbing materials, circuit boards, and various substrates and supports. . Most of the fibers and leathers that have been widely used in the past are polymer materials and porous materials. The first artificially produced foam was natural latex foam, and later, synthetic latex, etc. were used as raw materials for foam. Recently, various elastic plastic foams such as polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC) are developing, and the research on the types of foams and their foaming technology is actively conduct. Polyolefin foam is used in automobiles, packaging, construction, marine, medicine, sports, and leisure industries because of its excellent light weight, chemical resistance, impact absorption, heat insulation, and sound insulation. Among them, ethylene-acetic acid Ethylene (ethylene vinyl Acetate, EVA) has excellent flexibility, impact strength, transparency, processability, ozone resistance, etc., so it is widely used in the automotive industry and electrical and electronic products, etc., especially because of the low specific gravity and softness of the foam Its tactility and appropriate strength and impact characteristics are widely used as insoles and midsoles as cushioning materials in the shoe industry.

Generally, the physical properties of polymer foams are affected by the mechanical properties of the base resin of the foam and the cell structure such as open cell content, size, size distribution, and morphology, and are also affected by the concentration of crosslinking agents, nucleating agents, etc. A lot of research is being done on the influence of various variables such as additives and processing technology and processing conditions.

For example, Korean Patent No. 10-2017-0081949 discloses a microporous foamed nanocomposite material and a preparation method thereof. Polymers, chemical blowing agents, foam accelerators, and cross-linking agents can provide enhanced physical properties of microcellular foamed nanocomposites and enable large-scale commercial production.

In addition, Japanese Patent No. 6026895 discloses a foam resin composition comprising a biodegradable resin, a polypropylene resin, a flexible polymer and a nucleating agent, capable of providing a high foaming rate, excellent Strength, flexibility and resilience, wherein the biodegradable resin comprises starch.

In addition, Japanese Laid-Open Patent No. 2013-159632 provides a thermoplastic elastomer composition comprising an ethylene-vinyl acetate copolymer, a diene compound, and an olefin copolymer to provide a thermoplastic elastomer having excellent flexibility, moldability, strength, etc. Foam.

As mentioned above, for the foam composition intended to provide excellent physical properties Development is being actively carried out, and development research is still required in order to provide better physical properties. In view of the foregoing, the present invention has been accomplished to provide a highly functional foaming composition excellent in split tear strength and resiliency, particularly by adjusting the type and size of a nucleating agent contained in a polymer foam.

[Prior Art Literature]

(Patent Document 1) Korean Laid-Open Patent Publication No. 10-2017-0081949 (2017.07.13)

(Patent Document 2) Japanese Granted Patent Publication No. 6026895 (2016.11.16)

(Patent Document 3) Japanese Laid-Open Patent Publication No. 2013-159632 (2013.08.19)

The object of the present invention is to solve all the problems mentioned above.

An object of the present invention is to provide a highly functional foaming composition excellent in split tear strength and resilience. In particular, the purpose is to adjust the type and size of the nucleating agent contained in the polymer foam to improve mechanical properties.

An object of the present invention is to provide a highly functional foaming composition as a shoemaking material.

The characteristic configuration of the present invention aimed at achieving the object of the present invention described above and achieving the characteristic effects of the present invention described later is as follows.

According to an embodiment of the present invention, a resin composition for foaming is provided. With respect to 100 parts by weight of the blended resin, the resin composition for foaming includes 0.1 to 10 parts by weight of a silicon dioxide nucleating agent, 0.1 ~5 parts by weight of crosslinking agent, 1~20 parts by weight of foaming agent and 1~10 parts by weight of foaming aid.

According to an embodiment of the present invention, the blended resin contains 20-80 parts by weight of olefinic elastomer relative to 20-80 parts by weight of ethylene-vinyl acetate copolymer (EVA).

According to an embodiment of the present invention, there is provided a material comprising the resin composition for foaming, which can be used for shoemaking materials.

According to an embodiment of the present invention, there is provided a method for preparing a foaming resin composition, the method comprising the following steps: step (a), preparing a blend comprising ethylene-vinyl acetate copolymer (EVA) and an olefinic elastomer Resin; step (b), drop into silicon dioxide nucleating agent to described blended resin, and carry out kneading for the first time; Step (c), add crosslinking agent, blowing agent and foaming agent to described blended resin Auxiliary, and carry out the second kneading.

According to an embodiment of the present invention, the preparation method adopts a melt blending method, which can be selected from an extruder, a kneader (Kneader), a Brabender Plasticorder (Brabender Plasticorder), a mixer (Mixing Roll) ) and at least one of mixers.

According to the resin composition for foaming of the present invention, excellent split tear strength and resilience can be provided during foaming processing. In addition, it can provide excellent hardness, density and energy loss coefficient, so it can be used as a shoemaking material.

A shoemaking material comprising the foamable resin composition of the present invention can provide excellent abrasion resistance, impact resistance, and light weight.

FIG. 1 shows a scanning electron microscope (SEM) photograph of the foaming composition of Comparative Example 1 of the present invention.

Fig. 2 shows a scanning electron microscope (SEM) photograph of the foaming composition of Example 1 of the present invention.

The detailed description of the invention that follows will refer to specific embodiments in which the invention can be practiced. These embodiments are described in detail so as to enable those skilled in the art to practice the present invention. The various embodiments of the invention differ from each other but are not necessarily mutually exclusive. For example, specific properties, structures, and characteristics described herein can be associated with one embodiment, and can be implemented in other embodiments without departing from the spirit and scope of the present invention. In addition, it should be understood that the position or arrangement of individual constituent elements in each of the disclosed embodiments may be changed without departing from the spirit and scope of the invention. Therefore, the following detailed description is not intended to be limiting, and the scope of the present invention is only limited by the appended claims and their equivalents as long as it is properly stated.

Hereinafter, a detailed description will be given with reference to several preferred embodiments of the present invention, so that those skilled in the art can easily implement the present invention.

According to the present invention, a highly functional foaming resin composition and a method for producing the same are provided.

According to an embodiment of the present invention, the blend resin includes ethylene-vinyl acetate copolymer (EVA) and olefinic elastomer.

According to an embodiment of the present invention, the blended resin contains 80-20 parts by weight of olefin-based elastomer relative to 20-80 parts by weight of ethylene-vinyl acetate copolymer (EVA). In the blended resin, when the proportion of olefinic elastomer is less than 20 parts by weight, the crystallinity of the resin increases, resulting in a decrease in the elasticity of the resin, and when it is greater than 80 parts by weight, the processability decreases, and problems such as expansion ratio or split layer The physical properties of tear strength (STS) decreased.

The ethylene-vinyl acetate copolymer (ethylene-vinyl acetate, EVA) of the present invention refers to the polymer formed by the copolymerization of ethylene (ethylene) and vinyl acetate (vinyl acetate) monomers, usually, has The characteristics of the basic properties of the resulting polyethylene products and the properties of vinyl acetate. Compared with vinyl monomer, vinyl acetate monomer contains acetoxy, so the higher its content, the stronger the polar property. As the vinyl acetate content increases, optical properties (gloss) are improved, density increases, but flexibility increases due to decreased crystallinity. In addition, in the blended resin, the crosslinking reactivity of the crosslinking agent is affected by the molecular structure, and the more functional groups, the stronger the crosslinking reactivity.

The content of vinyl acetate (VA) in the ethylene-vinyl acetate copolymer (EVA) is 10 to 50% by weight. When the content is less than 10% by weight, it is difficult to process, and when it is more than 50% by weight, it is unfavorable for crystallinity. In addition, ethylene-vinyl acetate copolymer The greater the content of acetoxy (acetoxy), the better the crosslinking reactivity, but when it is too much, it is necessary to control the prevention of crosslinking in the process, so the above range is preferable.

The melt flow index of the ethylene-vinyl acetate copolymer (EVA) may be 1 to 10, and the viscosity analysis method is melt index (Melt Index), and the unit is g/10min. When the melt flow index is less than 1, the time required for the reaction is prolonged due to decreased fluidity, and when it is greater than 10, the elasticity and restoring force are decreased.

The purpose of the olefin-based elastomer in the present invention may be to maintain the melt strength (Melt Strength) of the resin during foaming of the resin composition. At this time, based on 125°C, the Mooney viscosity of the olefinic elastomer is 25-75. Mooney viscosity (Mooney viscosity) is a value indicating the viscosity of rubber, and affects the processability of rubber and the physical properties of rubber after vulcanization. By providing the olefin-based elastomer satisfying the above-mentioned range, it is possible to prevent the problem of a decrease in foaming processability due to high melt strength during foaming processing, and to provide excellent flexibility and processability.

According to an embodiment of the present invention, based on ASTM D1238, the melt index (MI) of the olefinic elastomer is 0.1~30g/10min under 2.16kg at 190°C, and the weight average molecular weight of the olefinic elastomer is 10,000 ~800,000g/mol.

According to an embodiment of the present invention, the olefinic elastomer includes at least one selected from C ₂ ~C ₂₀ α-olefins and ethylene-propylene copolymer rubber. The C ₂ -C ₂₀ α-olefin is preferably ethylene, and in this case, it may contain 40-90% by weight of ethylene. When ethylene is included in a range of 40 to 90% by weight, an appropriate hard segment can be provided, and therefore, excellent strength and moldability can be provided.

According to an embodiment of the present invention, the ethylene-propylene copolymer rubber can be It includes at least one selected from ethylene-propylene rubber (EPR) and ethylene-propylene-diene rubber (EPDM), and ethylene-propylene-diene rubber (EPDM) may be preferred.

According to an embodiment of the present invention, the ethylene propylene diene rubber (EPDM) includes ethylene, propylene and ethylidene norbornene (ENB). In this case, 40 to 80% by weight of ethylene, 10 to 50% by weight of propylene, and 0.5 to 10% by weight of ethylidene norbornene are contained.

According to an embodiment of the present invention, there is provided a resin composition for foaming, which contains 0.1-10 parts by weight of silica nucleating agent, 0.1-5 parts by weight of Joint agent, 1-20 parts by weight of foaming agent and 1-10 parts by weight of foaming aid.

More specifically, the blended resin may contain 80 to 20 parts by weight of olefinic elastomer relative to 20 to 80 parts by weight of ethylene-vinyl acetate copolymer (EVA), preferably relative to 40 to 60 parts by weight The ethylene-vinyl acetate copolymer (EVA) contains 60~40 parts by weight of ethylene-propylene-diene rubber (EPDM), so that the foam can be fully foamed, and can provide excellent elasticity and foaming composition Resilience.

In particular, according to an embodiment of the present invention, relative to 100 parts by weight of the blended resin, the silicon dioxide nucleating agent may contain 0.1-10 parts by weight, preferably 0.1-5 parts by weight. In view of the results in Table 2 of Examples described later, it can be confirmed that the physical properties of phylon prepared from a foaming composition containing 0.1 to 5 parts by weight of a silica nucleating agent are generally improved. In particular, excellent abrasion resistance and impact resistance can be expected in view of split tear strength (STS), resilience, and energy loss coefficient, and excellent lightness can be expected in view of hardness and density values.

According to an embodiment of the present invention, the silicon dioxide nucleating agent includes fumed silica, fused silica, precipitated silica, silica gel At least one of silica sol (colloidal silica) and crystalline silica (crystalline silica), preferably fumed silica. In view of the results in Table 2 of the examples described later, when a nano-sized silica nucleating agent is provided, excellent physical properties can be provided when the foaming composition forms a foam (foam), especially, a split tear can be provided. A foaming composition that is excellent in both burst strength (STS) and resilience, and excellent in hardness.

According to an embodiment of the present invention, the average particle size of the silicon dioxide nucleating agent is in the range of 1-50 nm, preferably 7-40 nm.

Generally, the smaller the particle size of the nucleating agent, the larger the specific surface area (BET), and the larger the specific surface area, the stronger the nucleating effect, thereby generating more microbubbles. In the case of generating uniform microbubbles, it is possible to improve the mechanical properties of the foam during foaming. Therefore, in order to form uniform microbubbles, a 7~40nm silica nucleating agent can be provided to change the cell morphology, thereby forming microbubbles and improving the mechanical properties of the foam. When it is less than 7nm, the specific surface area increases and the surface energy (Surface Energy) increases, which will cause the condensation of _SiO2 . When it is greater than 40nm, it is difficult to provide uniform microbubbles. Therefore, the above range is preferred. In view of the results of Table 2 described later, it can be confirmed that the foam mechanical property values are improved depending on the size of the nucleating agent.

According to an embodiment of the present invention, the crosslinking agent may be an organic peroxide, usually a dialkyl organic peroxide. For example, it can be selected from 1,1-ditertiary Butyl peroxide-3,3,5-trimethylcyclohexane, tert-butyl cumene peroxide, dicumyl peroxide (DCP), 2,5-dimethyl-2,5-di At least one of (tert-butylperoxy)hexane and 1,3-bis(tert-butylperoxyisopropyl)benzene, preferably dicumyl peroxide (DCP).

In particular, peroxides contained in organic peroxides are activated to provide sites for abstracting hydrogen atoms from the polymer backbone and performing crosslinking, thereby initiating the crosslinking process. The foam is crosslinked in this way during the foaming process, thereby making it possible to provide foam molded articles with improved physical properties. In particular, the crosslinking agent can impart the preferred viscoelasticity required for foaming. In addition, for cross-linking and foaming, it is preferable that ethylene-vinyl acetate copolymer (EVA) is firstly cross-linked by decomposition of a cross-linking agent to obtain proper viscoelasticity, and then, the blowing agent is decomposed to form cells. The expansion ratio is basically determined by the amount of blowing agent added, and the elasticity of ethylene-vinyl acetate copolymer (EVA) has a large relationship with the formation of bubbles. Therefore, when the blended resin contains 0.1~ When the cross-linking agent is 5 parts by weight, satisfactory physical properties of the final product can be provided.

According to an embodiment of the present invention, the foaming agent is an additive used to contain air bubbles in a resin such as rubber or plastic, and the chemical foaming agent can provide an organic foaming agent. For example, the organic foaming agent may include at least one selected from azodicarbonylamide, dinitrosopentamethylenetetramine, P,P'-oxobisbenzenesulfonylhydrazine, preferably azobis Formamide can also be denatured azodicarbonamide. For example, JTR-M is available commercially available.

In addition, with respect to 100 parts by weight of the blended resin, 1 to 20 parts by weight can be included A large amount of foaming agent, so as to provide light weight, cushioning, heat insulation and other physical properties, especially, in the case of shoe-making materials, it can provide shock absorption during strenuous exercise or walking effect. In addition, when the decomposition temperature is less than 130°C, the foaming agent has the problem of foaming at the initial stage of the reaction, and when it is greater than 200°C, the foaming time is too long and there is a problem in productivity. Therefore, it is preferably 130°C~200°C range.

According to an embodiment of the present invention, the foaming aid is a metal oxide, which may include at least one selected from zinc oxide, calcium oxide, magnesium oxide, tin oxide, cadmium oxide and lead oxide, and may be preferably zinc oxide. With respect to 100 parts by weight of the blended resin, 1 to 10 parts by weight of the foaming aid can be included, thereby adjusting the foaming speed of the resin composition, increasing the foaming rate, and adjusting the foaming density inside the foamed layer . For example, B-50 ZnO M/B of BUWON Corporation can be provided.

According to an embodiment of the present invention, in addition to the foaming agent and foaming aid, a bubble generation accelerator and a surfactant may be further added so as to be able to affect the formation of bubbles in the resin. In addition, at least one selected from stabilizers, antioxidants, fillers, and colorants may be included as needed to adjust physical properties, but is not limited thereto.

According to an embodiment of the present invention, a material including a resin composition for foaming is provided. The material can be applied to electronic component materials, machine parts materials, automobile parts materials, construction materials, packaging materials, etc., and is preferably used for shoemaking materials. It can be used for midsoles and insoles that require ultra-light weight, as well as uppers and outsoles that require abrasion resistance and impact absorption, and shoes. Heels, slippers soles, etc., but not limited to.

On the other hand, according to an embodiment of the present invention, there is provided a method for preparing a resin composition for foaming, the method comprising the following steps: step (a), preparing a foam containing ethylene-vinyl acetate copolymer (EVA) and an olefinic elastomer A blended resin of bulk resin; step (b), drop into the blended resin with a silicon dioxide nucleating agent, and carry out the first kneading; step (c), add a crosslinking agent, hair to the blended resin Foaming agent and foaming aid, and kneading for the second time. At this time, the preparation method is a melt blending method. Hereinafter, the composition included in the preparation method can apply the same content as the above-mentioned resin composition and proportion, and repeated explanations will be omitted.

According to an embodiment of the present invention, in the step (a), relative to 20-80 parts by weight of ethylene-vinyl acetate copolymer (EVA), the blended resin contains 20-80 parts by weight of olefinic elastomer. In addition, the olefin-based elastomer may contain at least one selected from C ₂ -C ₂₀ α-olefins and ethylene-propylene copolymer rubbers. At this time, the ethylene-propylene copolymer may be contained. Preferably, 60-40 parts by weight of ethylene-propylene-diene rubber (EPDM) is included with respect to 40-60 parts by weight of the ethylene-vinyl acetate copolymer (EVA). In this case, 40 to 80% by weight of ethylene, 10 to 50% by weight of propylene, and 0.5 to 10% by weight of ethylidene norbornene are contained.

According to an embodiment of the present invention, in the step (b), relative to 100 parts by weight of the blended resin, 0.1 to 10 parts by weight of a silicon dioxide nucleating agent is included, and the average value of the silicon dioxide nucleating agent The particle size is 1 to 50 nm, preferably 7 to 40 nm. The content and size of the silica nucleating agent are the same as those described above.

According to an embodiment of the present invention, in the step (b), the step of adding a silicon dioxide nucleating agent and performing the first kneading can be performed at 100° C. to 150° C. It can preferably be 100°C to 110°C, and it is preferable to add a non-reactive nucleating agent before other additive compositions.

According to an embodiment of the present invention, in the step (c), relative to 100 parts by weight of the blended resin, 0.1 to 5 parts by weight of a crosslinking agent, 1 to 20 parts by weight of a foaming agent and 1 to 2 parts by weight are included. 10 parts by weight of the foaming aid, and carry out the second kneading step. The temperature is the same as step (b), and can be carried out for 5 minutes to 15 minutes.

According to an embodiment of the present invention, the melt blending method refers to heating above the melting temperature of the polymer material to be blended (Blend) to melt it, and then using mechanical force to prepare a new substance. In the present invention, Compression may be performed after melting at the melting temperature of the resin.

According to an embodiment of the present invention, the melt blending method can be selected from an extruder, a kneader (Kneader), a Brabender plasticizer (Brabender Plasticorder), a mixer (Mixing Roll) and a mixer at least one of the

According to an embodiment of the present invention, the extruder is preferably a melting extruder, which can optimize the process conditions and implement the process according to various raw materials input in the melting process. In the melting process, the melting temperature may be 100°C to 300°C, preferably 150°C to 230°C. At this time, the melt flow index can be 0.1 to 60, and the viscosity analysis method is melt index (Melt Index), and the unit is g/10min.

According to an embodiment of the present invention, the extruder can be any one selected from a single-screw extruder, a twin-screw extruder, a single-screw extruder and a twin-screw extruder, and a twin-screw extruder can be preferred. Exit.

Below, through preferred embodiment of the present invention, to the constitution of the present invention and effect Describe in more detail. However, this is a preferred example of the present invention, and it should not be interpreted that the present invention is limited thereto in any sense.

Contents not described here are those that can be sufficiently deduced by those skilled in the art, and therefore explanations thereof are omitted.

Preparation Example 1: Preparation of Foaming Resin Composition

A twin screw extruder (27 mm Φ) from Leistritz was used, and the processing temperature was 140-160° C. to prepare a blended (Blend) resin. The screw speed is 200~250rpm, and the feeding speed is 8~9kg/h.

After that, in the Two Roll-mill (Two Roll-mill), put in a non-reactive nucleating agent at a temperature of 100~110°C, and knead for the first time, and then add a crosslinking agent, a foaming agent and foaming aid, and further kneaded for 5 minutes, thereby minimizing the early decomposition of the foaming agent that may occur in the process of preparing the blend, and preparing a resin composition for foaming.

Preparation Example 2: Preparation of Foam (Pre-Form) and Phylon

Put 87g of sheet-shaped (Sheet) resin composition for foaming into the corresponding foaming mold, and under the conditions of 150kg/cm ² and 165°C, crosslink/foam for 10 minutes to prepare a preform (Pre -Form) (180% expansion ratio). The 10mm-thick sample for physical property measurement was made into a phylon form by cutting (Cutting) the preform (Pre-Form) with a slicer (Slicer) and then compressing it. Cut the preform (Pre-Form) into a size of 80×180×18 (W×L×H, mm) and put it into a phylon molding mold. After heating at 165°C for 380 seconds, cooling for 380 seconds, compression molding is 10mm thickness to prepare phylon.

Example 1

The resin provided in Preparation Example 1 is a blended resin, which contains 5 parts by weight of silicon dioxide with respect to 50 parts by weight of ethylene-vinyl acetate copolymer (EVA) and 50 parts by weight of ethylene-propylene-diene rubber (EPDM). Nucleating agent, 0.6 parts by weight of crosslinking agent (DCP), 10.4 parts by weight of foaming agent (JRT-M) and 3 parts by weight of foaming aid (MB).

At this time, the nucleating agent is silicon dioxide nucleating agent (OCI KONASIL K-300), with a size of 7-40nm.

According to Preparation Example 2, the foaming resin composition of Preparation Example 1 was made into a preform (Pre-Form), and the results of the test according to the experimental example in Table 1 below are shown in Table 2.

Comparative example 1

It carried out in the same manner as Example 1 except that the nucleating agent was a silica nucleating agent (DEUREX S3012M) and the size was 12 μm or less.

Comparative example 2

It carried out in the same manner as Example 1 except that the nucleating agent was a silica nucleating agent (DEUREX S3017M) and the size was 17 μm or less.

Comparative example 3

The procedure was carried out in the same manner as in Example 1, except that a silicon dioxide nucleating agent (ABC Nanotech SILNOS 230) was provided as the nucleating agent and the size was 2-4 μm or less.

Comparative example 4

It carried out in the same manner as in Example 1 except that the nucleating agent was a calcium carbonate nucleating agent (BUWON B-50 M/B) and the size was 50 μm or less.

Comparative Example 5

It was performed in the same manner as in Example 1 except that the nucleating agent was talc (KOCH KC-5000C) and the size was 3.5±0.5 μm.

Comparative example 6

It was performed in the same manner as in Example 1 except that the nucleating agent was talc (KOCH KCNAP-400) and the size was 11.0±2.0 μm.

Example 2~Example 6

In addition to the nucleating agent comprising 0.1 parts by weight in Example 2, the nucleating agent comprising 0.3 parts by weight in Example 3, the nucleating agent comprising 0.7 parts by weight in Example 4, and the nucleating agent comprising 1 part by weight in Example 5 The nucleating agent was carried out in the same manner as in Example 1 except that 3 parts by weight of the nucleating agent was included in Example 6.

Comparative Example 7

It was performed in the same manner as in Example 1 except that the nucleating agent was not included.

Experimental example: physical property evaluation

As shown in Table 1 below, physical property evaluations were performed on the foams (Pre-Forms) and phylons prepared in accordance with the above Examples and Comparative Examples.

Looking at Table 2, which is the evaluation results of physical properties in Table 1, it can be confirmed that in Example 1 in which the size of the silica nucleating agent is 7 to 40 nm, the cell morphology can be changed when forming foam (foam) , forming microbubbles and thus improving the mechanical properties of the foam.

Looking at Table 2, it can be confirmed that in the measured values of phylon physical properties of different nucleating agents, the more nano-sized silica nucleating agent is contained, the greater the split tear strength (STS) , but the resilience is smaller. Therefore, it can be confirmed that Example 3 is the optimum numerical value, and in Example 3, while providing an appropriate split tear strength (STS) of 2.0 kgf/cm or more, both the rebound resilience and the energy loss coefficient are excellent.

That is, it can be confirmed through experiments that the particle size has the greatest influence on the nucleating effect, and the nucleating agent of nano-sized particles improves the nucleating effect because of its large specific surface area, thereby providing a foam with microbubbles, and then can We provide foaming compositions that are excellent in both split tear strength (STS) and resilience, and are excellent in elasticity and hardness.

Therefore, it was confirmed that by providing the foaming composition of the present invention, a high-function composition excellent in split tear strength and resilience can be provided, and it can be used as a shoemaking material.

Above, the present invention has been described through specific items such as specific constituent elements and limited embodiments, but this is only for a more comprehensive understanding of the present invention. The present invention is not limited to the above-mentioned multiple embodiments, and those skilled in the art can Various modifications and variations are made from these descriptions.

Therefore, the idea of the present invention is not limited to the embodiments described above, and the appended claims and their equivalents or equivalents all belong to the category of the idea of the present invention.

Claims (20)

A resin composition for foaming, characterized in that, relative to 100 parts by weight of the blended resin, it comprises 0.1 to 10 parts by weight of a silicon dioxide nucleating agent, 0.1 to 5 parts by weight of a crosslinking agent, 1 to 20 parts by weight of Parts of foaming agent and 1 to 10 parts by weight of foaming aid, in the blended resin, relative to 20 to 80 parts by weight of ethylene-vinyl acetate copolymer (EVA), 80 to 20 parts by weight of olefin Elastomer, the content of vinyl acetate (VA) in the ethylene-vinyl acetate copolymer (EVA) is 10 to 50% by weight. The foaming resin composition according to claim 1, wherein, in the blended resin, 60 to 40 parts by weight of ethylene-vinyl acetate copolymer (EVA) is included in 40 to 60 parts by weight of Ethylene Propylene Diene Monomer (EPDM). The foaming resin composition according to claim 1, wherein the olefinic elastomer comprises at least one selected from C ₂ to C ₂₀ α-olefins and ethylene-propylene copolymer rubbers. The foaming resin composition according to claim 3, wherein the ethylene-propylene copolymer rubber includes at least one selected from ethylene-propylene rubber (EPR) and ethylene-propylene-diene rubber (EPDM). The foaming resin composition according to claim 4, wherein the ethylene-propylene-diene rubber (EPDM) comprises 40 to 80% by weight of ethylene, 10 to 50% by weight of propylene, and 0.5 to 10% by weight of ethylidene norbornene. The resin composition for foaming according to Claim 1, wherein the olefinic elastomer has a Mooney viscosity of 10-100 based on 125°C. The resin composition for foaming according to claim 1, wherein the average particle diameter of the silica nucleating agent is 1 to 50 nm. According to the resin composition for foaming according to claim 1, it is characterized in that, the silica nucleating agent comprises fumed silica, fused silica, precipitated silica, silica gel, silica sol, crystallized silica At least one of silicon oxide. According to the foaming resin composition described in Claim 1, it is characterized in that the crosslinking agent comprises 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, tert-butylcumene peroxide, dicumyl peroxide (DCP), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and 1,3-bis(tert- At least one of butylperoxyisopropyl)benzene. According to the foaming resin composition described in claim 1, it is characterized in that the foaming agent comprises azodicarbonamide, dinitrosopentamethylenetetramine, P,P'-oxygen At least one of the two phenylsulfonyl hydrazines. The foaming resin composition according to claim 1, wherein the foaming aid includes at least one selected from zinc oxide, calcium oxide, magnesium oxide, tin oxide, cadmium oxide and lead oxide. A material comprising a foaming resin composition, characterized by comprising the foaming resin composition according to any one of claims 1 to 11. The material comprising the foaming resin composition according to claim 12 is characterized in that the material can be applied to materials selected from electronic component materials, mechanical parts materials, auto parts materials, building materials, packaging materials and manufacturing At least one of the shoe materials. A kind of preparation method of resin composition for foaming, is characterized in that, comprises the following steps: Step (a), prepares the blended resin that comprises ethylene-vinyl acetate copolymer (EVA) and olefinic elastomer; Step (b), Putting a silicon dioxide nucleating agent into the blended resin, and performing the first kneading; and step (c), adding a crosslinking agent, a foaming agent and a foaming aid to the blended resin, and performing the second For secondary kneading, the content of vinyl acetate (VA) in the ethylene-vinyl acetate copolymer (EVA) is 10 to 50% by weight. According to the preparation method of the foaming resin composition described in claim 14, it is characterized in that, in the blended resin of the step (a), relative to 20 to 80 parts by weight of ethylene-vinyl acetate copolymer (EVA ), comprising 20 to 80 parts by weight of an olefinic elastomer. According to the preparation method of the foaming resin composition described in claim 14, it is characterized in that, in the step (b), relative to 100 parts by weight of the blended resin, 0.1 to 10 parts by weight of silicon dioxide are included Nucleating agent. According to the preparation method of the foaming resin composition described in Claim 14, it is characterized in that, in the step (b), the average particle diameter of the silica nucleating agent is 1-50 nm. According to the preparation method of the foaming resin composition described in Claim 14, it is characterized in that the step (b) is carried out at 100°C to 150°C. According to the preparation method of the foaming resin composition described in claim 14, it is characterized in that, in the step (c), relative to 100 parts by weight of the blended resin, 0.1 to 5 parts by weight of a crosslinking agent are included , 1-20 parts by weight of foaming agent and 1-10 parts by weight of foaming aid. According to the preparation method of the foaming resin composition described in claim 14, it is characterized in that, the preparation method adopts a melt blending method, using a compound selected from extruder, kneader (Kneader), Brabender plasticizing At least one of a Brabender Plasticorder, a Mixing Roll and a mixer.

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