KR102588768B1 - Microwave heat moldable polymer composition and molding method of foam composition using the same - Google Patents

Abstract

The polymer composition moldable by microwaves and the method of molding a foam composition using the same of the present invention have the effect of enabling polymers that do not react to microwaves to be molded by microwaves through a simple process using an additive composition heated by microwaves.
In addition, the polymer composition moldable by microwaves of the present invention and the method of molding a foam composition using the same have excellent energy efficiency and reduce the inconvenience of the process by heating using microwaves.

Description

Microwave-mouldable polymer composition and method of forming a foam composition using the same {MICROWAVE HEAT MOLDABLE POLYMER COMPOSITION AND MOLDING METHOD OF FOAM COMPOSITION USING THE SAME}

The present invention relates to a polymer composition that can be molded by microwaves and a method of molding a foam composition using the same. More specifically, it relates to a polymer composition that can be molded by microwaves and a method of molding a foam composition using the same. More specifically, it relates to a polymer composition that does not react to microwaves, which can be used as a foam, etc. by using an additive composition heated by microwaves. It relates to a polymer composition that can be molded by microwaves and a method of molding a foam composition using the same.

Shoes and similar products are made of materials made of rubber, foam, etc. that sometimes require heating and curing (cross-linking), and through this curing process, various materials can be used to manufacture shoes and similar products. For example, a curing process can activate an adhesive used to join two or more components. Additionally, a crosslinking process may be necessary to mold foam materials such as ethylene vinyl acetate (EVA), which are mainly included in the soles of shoes.

In relation to this, heating and crosslinking processes were conventionally performed using an oven, heat press, etc. However, in this case, there is a problem in that some materials do not respond sufficiently to the heating temperature and/or duration. In addition, the crosslinking process using a conventional oven and heat press relies on conduction and/or radiation, so the manufacturing process has the disadvantages of low efficiency, high process costs, and a long time.

Accordingly, recently, technology that performs a heat generation process by irradiating microwaves has been attracting attention. Microwaves generally have a frequency of 300 to 30,000 megacycles and a wavelength of less than 1 m. 1 m to 10 cm are called decimeter waves, and 1 cm to 1 mm are called millimeter waves. On the other hand, when microwaves are irradiated to a material, the material itself can be affected, which can be used for heating or chemical reactions. When heating a material using microwaves, self-heating occurs within the material, so it can be heated more quickly and more uniformly than the existing external heating method using oil or electricity, which is heated by heat transfer from the outside through the wall and material. Therefore, heating using microwaves has the advantage of being more energy efficient than existing heating methods using heat sources.

Research on using microwaves for chemical reactions is very old and is also used commercially in the polymer materials industry. Melamine and polyimide foam, which are used as insulation and sound insulating materials, can be manufactured using microwaves. Despite the various advantages of microwaves, most polymers do not respond to microwaves, which poses limitations in their utilization and application.

In this regard, U.S. Patent Publication No. 2017-0073490 discloses a process for manufacturing thermoplastic polyurethane (TPU) molded foam using microwaves. Through this, it is possible to solve the reduced value of manufactured products, excessive energy consumption, and process inconvenience when using conventional heating or curing processes. However, it is still difficult to utilize polymer materials that are not reactive to microwaves, except for thermoplastic polyurethane, and when the manufactured foam reacts to microwaves, foaming gas escapes and is lost and settles down, making molding difficult.

U.S. Published Patent 2017-0073490

The present invention was created to solve the above-mentioned problems, and the first problem that the present invention aims to solve is to mold polymers that do not react to microwaves or polymers with low reactivity in microwaves using an additive composition heated by microwaves. The aim is to provide a possible polymer composition and a method of molding a foam composition using the same.

In addition, the second problem to be solved by the present invention is to manufacture a foam composition using the above-described polymer composition, and to provide a polymer composition that can be molded by microwaves to produce various molded products by molding the foam composition, and a method of molding a foam composition using the same. It is done.

In order to solve the above-described problems, the present invention provides a polymer that does not react exothermically with microwaves; and an additive that reacts exothermically with microwaves, wherein the additive is at least one selected from the group consisting of hydroxy compounds, plasticizer compounds, and absorbent polymers. .

According to a preferred embodiment of the present invention, the hydroxy compound is a group consisting of polyethylene glycol (PEG), diethylene glycol (DEG), triethylene glycol (TEG), tripropylene glycol (TPG), and 1,4-butanediol. It may be any one or more selected from.

According to a preferred embodiment of the present invention, the absorbent polymer may be any one or more selected from the group consisting of starch-based compounds, cellulose-based compounds, acrylic acid-based compounds, vinyl alcohol-based compounds, and ethylene oxide-based compounds.

According to a preferred embodiment of the present invention, the absorbent polymer may be any one or more selected from the group consisting of polyacrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, and cellulose. there is.

According to a preferred embodiment of the present invention, when the additive is a hydroxy compound or a plasticizer type compound, the additive may be included while supported on a porous material.

According to a preferred embodiment of the present invention, when the additive is an absorbent polymer, the additive may be included in a state in which water has been absorbed.

According to a preferred embodiment of the present invention, the porous material may be any one or more selected from the group consisting of silica, alumina, niobium, tantalum, zirconium, carbon, magnesium, titanium, and polymers.

According to a preferred embodiment of the present invention, it may further include any one or more selected from the group consisting of peroxide, foaming agent, and metal oxide.

In addition, the present invention includes the steps of (1) producing a bead-type foam containing the polymer composition of claim 1 and a blowing agent; (2) injecting the bead-shaped foam into a mold made of a material that does not react to microwaves and then heat-sealing it by irradiating it with microwaves; and (3) cooling the heat-sealed bead-shaped foam to obtain a molded product.

According to a preferred embodiment of the present invention, when irradiated with microwaves in step (2), the bead-shaped foam can be expanded without losing gas.

The polymer composition moldable by microwaves and the method of molding a foam composition using the same of the present invention have the effect of enabling polymers that do not react to microwaves to be molded by microwaves through a simple process using an additive composition heated by microwaves.

In addition, the polymer composition moldable by microwaves of the present invention and the method of molding a foam composition using the same have excellent energy efficiency and reduce the inconvenience of the process by heating using microwaves.

In addition, the polymer composition moldable by microwaves of the present invention and the method of molding a foam composition using the same allow the manufactured foam to be molded in an expanded state without loss of foaming gas when it reacts with microwaves, enabling the production of various molded products. There is an effect.

Figure 1 is a process flow diagram of a method for molding a foam composition using a polymer composition moldable by microwaves according to a preferred embodiment of the present invention.
Figure 2 is a technical flow chart showing the process of manufacturing a bead-type foam according to a preferred embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention.

First, the terms used in the present invention will be briefly explained.

The term “non-exothermic” refers to a state in which there is no or low reactivity when irradiated with microwaves, and the state does not easily generate heat below 100°C even when irradiated for approximately 5 minutes.

The term “exothermic reaction” refers to a state in which a product is reactive when irradiated with microwaves and easily generates heat above 150°C when irradiated for 1 to 3 minutes.

As described above, the heating and crosslinking process using conventional ovens, heat presses, etc. is a disadvantage in the manufacturing process because some materials do not respond sufficiently to the heating temperature and/or duration and rely on conduction and/or radiation. It had limitations such as low efficiency, high process costs, and long time commitment. In addition, the heating and curing process using microwaves had limitations in that it was difficult to use polymer materials that were not reactive to microwaves, and when the manufactured foam reacted to microwaves, the foaming gas was lost and settled down, making molding difficult.

Accordingly, the present invention provides a polymer that does not react exothermically with microwaves; and an additive that reacts exothermically with microwaves, wherein the additive is at least one selected from the group consisting of hydroxy compounds, plasticizer compounds, and absorbent polymers. A solution to the above-mentioned limitations was sought.

Through this, polymers that do not react to microwaves can be molded with microwaves through a simple process using additives heated by microwaves. At the same time, by heating using microwaves, energy efficiency is excellent and process efficiency can be significantly improved. In addition, when the foam manufactured using the composition reacts with microwaves, the foaming gas is not lost and can be molded in an expanded state, so it has the advantage of being used in the production of various products.

Polymers that do not react exothermically with microwaves are polymer resins that have no or low reactivity to microwaves and do not sufficiently generate heat even when irradiated with microwaves. Known polymers can be used without restrictions depending on the intended use or usage environment of the final product. .

Preferably, ethylene vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyurethane (PU, poly urethane), olefin block copolymer (OBC), and polyethylene ( Any one or more selected from the group consisting of PE (poly ethylene) can be used, and more preferably, ethylene vinyl acetate copolymer (EVA) can be used. When using ethylene vinyl acetate copolymer (EVA), it has excellent elasticity and low-temperature heat sealability, and can be used for a variety of purposes because it is soft and has good physical properties. In addition, it has excellent shock mitigation properties, making it suitable for manufacturing sports goods and footwear.

Additives that react exothermically with microwaves have good reactivity and can easily generate heat when irradiated with microwaves. Accordingly, it is possible to manufacture a polymer composition that can be molded by microwaves by using a variety of polymers that do not react exothermically with microwaves without any restrictions. In other words, by using the additive, the microwave process can be applied not only to polymers that react to microwaves but also to polymers that do not react to microwaves.

The additive that reacts exothermically with microwaves is at least one selected from the group consisting of hydroxy compounds, plasticizer compounds, and absorbent polymers. When using the above materials as additives, a variety of polymers suitable for the intended manufacturing purpose can be selected without limitation, and a polymer composition that can be molded by a microwave with excellent energy efficiency can be obtained.

According to a preferred embodiment of the present invention, the hydroxy compound may be a low molecular weight polyol with a molecular weight of 1,000 or less. Preferably, it may be at least one selected from the group consisting of polyethylene glycol (PEG), diethylene glycol (DEG), triethylene glycol (TEG), tripropylene glycol (TPG), and 1,4-butanediol. More preferably, it may be at least one selected from the group consisting of polyethylene glycol (PEG) and diethylene glycol (DEG), and even more preferably it may be polyethylene glycol (PEG). Since polar materials containing such hydroxyl groups (-OH) are easy to heat by microwaves, they can be used with polymers that do not heat through most of the microwaves and can be used to add microwave-moldable properties to polymer compositions. You can.

Plasticizer compounds can be used without limitation as long as they are easy to mix with the polymers included in the polymer composition and can increase flexibility, processability, and expandability, for example, phthalate-based, adipate-based, trimellitate-based, and terelate compounds. Phthalate-based materials, etc. can be used.

Meanwhile, according to a preferred embodiment of the present invention, when the additive is a hydroxy compound or a plasticizer type compound, the additive may be included while supported on a porous material. This is because it is difficult to use hydroxy compounds directly in polymers, so it is effective to use them as additives to polymer compositions while supporting them in a porous material.

At this time, the porous material can be used without limitation on the size of the pores as long as it supports a hydroxy compound or a plasticizer compound and can be used as an additive in that state, but is preferably silica, alumina, niobium, tantalum, zirconium, It may be any one or more selected from the group consisting of carbon, magnesium, titanium, and polymers. More preferably, it may be synthetic silica (Z-155, Z-175). In this case, there is an advantage that it can be included in the polymer composition while effectively supporting hydroxy compounds or plasticizer compounds.

A method commonly used in the relevant technical field may be used to support a hydroxy compound or plasticizer compound on a porous carrier. Preferably, a sealed mixer, such as a kneader or super mixer, can be used. In the closed mixer, the hydroxy compound or plasticizer compound can be stirred at an appropriate ratio according to the specific surface area of the porous body and supported on the porous carrier. For example, a hydroxy compound or plasticizer compound and porous silica can be stirred at a 1:1 weight ratio.

It is preferable that the absorbent polymer is included in a state in which water has been absorbed rather than used on its own. According to a preferred embodiment of the present invention, the absorbent polymer can be manufactured into fine particles while absorbing water and used as an additive. In this case, the additive has an easy exothermic reaction with respect to microwaves, which has the effect of imparting properties that can be molded by microwaves to the polymer composition of the present invention.

The absorbent polymer is preferably one or more selected from the group consisting of starch-based compounds, cellulose-based compounds, acrylic acid-based compounds, vinyl alcohol-based compounds, and ethylene oxide-based compounds. More preferably, any one or more selected from the group consisting of polyacrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, cellulose, and chitosan can be used. When the above materials are used as additives of the present invention in a water-absorbed state, there is an effect of increasing reactivity to microwaves.

Additionally, according to a preferred embodiment of the present invention, the additive may be included in an amount of 5 to 30 parts by weight based on 100 parts by weight of the polymer. More preferably, the additive may be included in an amount of 8 to 25 parts by weight based on 100 parts by weight of the polymer, and more preferably, it may be included in an amount of 10 to 20 parts by weight.

When the polymer composition of the present invention contains an additive within the above range, the polymer composition can be given reactivity to microwaves, which has the effect of allowing the polymer composition to be molded by irradiating microwaves. If the additive is included in an amount below the above range, the polymer composition may not have sufficient reactivity to microwaves, and if the additive is included in excess of the above range, the properties of the polymer composition are deteriorated, such as elasticity and physical properties. Problems such as deterioration of the back may occur.

According to a preferred embodiment of the present invention, the microwave-moldable polymer composition of the present invention may further include one or more selected from the group consisting of peroxides, blowing agents, and metal oxides.

The foaming agent is a substance that creates bubbles by mixing with a polymer that does not react exothermically with the microwave of the present invention. It can be widely used in the relevant technical field for the manufacture of shoes and similar products, but is preferably azodicarbonamide. (ADCA) series, dinitrosopentamethylene tetramine (DPT) series. It may be at least one selected from the group consisting of toluene sulfonyl hydrazide (TSH)-based, inorganic-based, and capsule-type foaming agents (Micropearl).

According to a preferred embodiment of the present invention, the foaming agent may be included in an amount of 0.5 to 10 parts by weight, more preferably in an amount of 1 to 7 parts by weight, and even more preferably in an amount of 2 parts by weight, based on 100 parts by weight of the polymer. You can. When the above range is satisfied, bubbles suitable for producing a polymer composition that can be molded in a microwave by mixing with a polymer can be created.

In the present invention, peroxide increases the viscosity of the polymer composition through a crosslinking reaction to hinder or prevent foaming gas loss, and can be widely used in the relevant technical field, preferably benzoyl peroxide (BPO) or diqueous peroxide. Wheat (DCP, dicumyl peroxide), etc. can be used.

According to a preferred embodiment of the present invention, the peroxide may be included in an amount of 0.05 to 1 part by weight, more preferably 0.1 to 0.5 parts by weight, and even more preferably 0.25 to 0.35 parts by weight, based on 100 parts by weight of the polymer. It may be included as a part.

Metal oxides can be added as crosslinking activators and reinforcing agents to control the crosslinking speed and promote decomposition of foaming agents, which are general functions. However, in this technology using microwaves, simple additives commonly used in the relevant technical field can be used.

Meanwhile, the microwave-mouldable polymer composition of the present invention may further include crosslinking aids, stearic acid, fillers, etc. in addition to the above-mentioned materials within the range that does not impair the physical properties desired by the present invention.

Stearic acid can be added as an internal release agent to improve storage stability and processability, and is preferably included in an amount of 0.5 to 1 part by weight based on 100 parts by weight of the thermoplastic polymer mixture. If the stearic acid content does not satisfy the above range, storage stability may be reduced or processingability may be difficult to control.

In addition, the ethylene vinyl acetate copolymer may be preferably included in an amount of 2 to 20 parts by weight, and more preferably in an amount of 5 to 15 parts by weight, based on 100 parts by weight of the microwave-mouldable polymer composition. If the content of the anti-early foam additive is less than the above range, the viscosity control effect may be reduced and a problem of early foaming may occur. If the content of the anti-early foam additive is more than the above range, the overall composition may be affected. This may cause problems such as deterioration in mechanical properties and heat resistance.

Meanwhile, the microwave-moldable polymer composition of the present invention can be widely used in the manufacture of various product groups, but is preferably used for manufacturing footwear.

As shown in Figure 1, the present invention includes (1) preparing a bead-shaped foam containing a polymer composition moldable by a microwave of the present invention and a foaming agent (S1), (2) preparing the bead-shaped foam in a microwave. A step (S2) of injecting into a mold made of a material that does not react and irradiating microwaves to heat-seal and mold it; and (3) cooling the heat-sealed bead-shaped foam to obtain a molded product (S3). Provided is a method of molding a foam composition using a polymer composition that can be molded by microwaves.

Through this, polymers that do not react to microwaves can be molded with microwaves through a simple process using additives heated by microwaves. At the same time, by heating using microwaves, energy efficiency is excellent and process efficiency can be significantly improved. In addition, when the foam manufactured using the composition reacts with microwaves, the foaming gas is not lost and can be molded in an expanded state, so it has the advantage of being used in the production of various products.

Hereinafter, it will be described in detail, excluding content that overlaps with the above-described content.

First, (1) the step (S1) of manufacturing a bead-shaped foam containing a polymer composition moldable by a microwave and a foaming agent of the present invention (S1) will be described.

A foam composition is prepared by mixing the microwave moldable polymer composition of the present invention and the foaming agent. The foaming agent may be included in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the polymer included in the polymer composition.

At this time, the method for producing the polymer composition moldable by microwaves can be a method commonly used in the relevant technical field. Preferably, it can be produced by stirring using a closed mixer, for example, a kneader or a super mixer. At this time, the temperature may vary depending on the melting point of the material, and may preferably be at least 40°C lower than the 1-minute half-life temperature of the crosslinking agent used.

Meanwhile, Figure 2 is a technical flow chart showing the process of manufacturing a bead-type foam according to a preferred embodiment of the present invention. Referring to Figure 2, the foam is prepared by (1) stirring the polymer composition and the foaming agent to prepare a mixed composition (S1-1), (2) dispersing and extruding the mixed composition to produce pellets (S1-1). It can be prepared through steps 2) and (3) crosslinking the pellet to obtain a bead-shaped foam (S1-3).

(1) The step (S1-1) of preparing a mixed composition by stirring the polymer composition and the foaming agent can be performed using a method commonly used in the relevant technical field, but is preferably performed using a closed mixer, such as a kneader or a super mixer. It can be stirred using, etc.

(2) The step (S1-2) of dispersing and extruding the mixed composition to produce pellets may be performed using a method commonly used in the relevant technical field, but preferably, the mixed composition is dispersed in an open roll mill and an extruder or Pellets can be manufactured using a pelletizer.

(3) The step (S1-3) of cross-linking and foaming the pellets to obtain a bead-shaped foam may be performed by cross-linking and foaming the pellets through a microwave process, or may be performed by cross-linking with a hot air blower or hot air oven. . In the case of cross-linking foaming, the exterior of the foam is manufactured in the form of beads (particles).

Next, the step (2) of injecting the bead-shaped foam into a mold made of a material that does not react to microwaves and then heat-sealing it by irradiating it with microwaves (S2) will be described.

The bead-shaped foam prepared in step (1) above is injected into a mold and molded through heat fusion by irradiating microwaves. At this time, the mold must be made of a material that does not react to microwaves.

Microwaves are irradiated at predetermined intervals for 3 minutes or less, preferably 2 minutes or less. In addition, preferably, the microwave can be radiated with an output of 1 to 20 kw, more preferably with an output of 3 to 12 kw, and even more preferably with an output of 4 to 8 kw. And, most preferably, it can be irradiated with an output of 6 kw.

When microwaves are irradiated at the above time, time interval, and power, the exothermic reaction of the bead-shaped foam of the present invention can easily occur, resulting in effective heat fusion molding.

Meanwhile, according to a preferred embodiment of the present invention, when irradiated with microwaves in step (2), the bead-shaped foam can be expanded without losing gas. That is, in the past, even if foam was manufactured using a polymer that reacts to microwaves and then molded by irradiating microwaves, there was a problem in that the foaming gas was lost and the foam settled down. However, the present invention has the effect of allowing the foaming gas to expand without loss even when irradiated with microwaves, thereby easily performing heat fusion molding.

Next, (3) the step (S3) of cooling the heat-sealed molded bead-shaped foam to obtain a molded product will be described.

As described above, a molded article (product or part) is obtained by cooling the bead-shaped foam that is heated, expanded, and heat-sealed through a microwave process. At this time, the cooling temperature and cooling method can be performed by methods commonly used in the relevant technical field.

Ultimately, the present invention can enable most polymers that do not react to microwaves to be molded with microwaves through a simple process using an additive composition heated with microwaves. The microwave process has excellent energy efficiency and has the advantage of significantly improving process efficiency. Therefore, the present invention is not limited to applying the microwave process with excellent process efficiency to some polymers that are reactive to microwaves, but can be applied to most polymers that are not reactive to microwaves, significantly expanding the scope of technical application. It works.

In addition, when the foam manufactured through the present invention reacts with microwaves, the foaming gas is not lost and can be molded in an expanded state, thereby improving the quality of the final product and making it possible to use it in various products such as footwear and similar products. There is an advantage.

Hereinafter, the present invention will be described in more detail through specific examples.

Example One

Porous silica (Z-155) and polyethylene glycol (PEG 300) were prepared by stirring in a kneader at a weight ratio of 1:1. A polymer composition was prepared by stirring polyethylene glycol (PEG) and ethylene vinyl acetate copolymer (EVA) resin (EVA 1317) supported on porous silica at 85-100°C in a kneader. At this time, the additive having a mixing ratio of porous silica and polyethylene glycol at a weight ratio of 1:1 was added in an amount of 20 parts by weight based on 100 parts by weight of ethylene vinyl acetate copolymer (EVA). Additionally, the polymer composition was dispersed in an open roll mill and pellets were manufactured using a pelletizer. The pellet was irradiated with a microwave at 1 kW output for 5 minutes to check the temperature change.

Example 2

The same procedure as Example 1 was performed except that a plasticizer (GL500-LG Chemical) supported on porous silica (Z-155) was used instead of polyethylene glycol (PEG) supported on porous silica (Z-155).

Example 3

When manufacturing polymer compositions The same procedure as Example 1 was performed except that 0.25 parts by weight of peroxide (BPO) and 2.0 parts by weight of foaming agent (ADCA) were added based on 100 parts by weight of ethylene vinyl acetate (EVA). The pellet was irradiated with a microwave at 1 kW output for 5 minutes to check the temperature change.

In addition, the pellets were pre-crosslinked through a twin-screw extruder, and then foam beads were prepared in an oven at 200°C. After the bead-shaped foam was put into the mold, it was molded by heat fusion by irradiating a microwave with an output of 6 kw for 60 seconds. Afterwards, the product was manufactured by cooling to below 40°C.

Example 4

When preparing the polymer composition, the same procedure as Example 3 was performed except that 0.25 parts by weight of peroxide, 2.0 parts by weight of foaming agent, and 10 parts by weight of titanium dioxide (TiO ₂ ) were added to 100 parts by weight of ethylene vinyl acetate (EVA).

Example 5

When manufacturing a polymer composition, water supported on porous silica (Z-155) is used instead of polyethylene glycol (PEG) supported on porous silica (Z-155). When manufacturing the polymer composition, 0.25 parts by weight of peroxide, 2.0 parts by weight of foaming agent, 10 parts by weight of titanium dioxide (TiO ₂ ), and 20 parts by weight of magnesium carbonate (MgCO ₃ ) were added to 100 parts by weight of ethylene vinyl acetate (EVA). The same procedure as in Example 3 was carried out.

Example 6

The same procedure as Example 1 was performed except that 10 parts by weight of polyethylene glycol (PEG) per 100 parts by weight of ethylene vinyl acetate (EVA) was used instead of polyethylene glycol (PEG) supported on porous silica (Z-155).

Example 7

The same procedure as Example 1 was carried out except that 10 parts by weight of a plasticizer per 100 parts by weight of ethylene vinyl acetate (EVA) was used instead of polyethylene glycol (PEG) supported on porous silica (Z-155).

Comparative example One

The same procedure as Example 1 was performed except that polyethylene glycol (PEG) supported on porous silica was not used.

Experiment example 1. Measurement of reaction temperature

For each Example and Comparative Example, 50 g of paper cups were put into a microwave (1 kW) to check the temperature change over time, and are shown in Table 1 below. At this time, checking the temperature takes 5 to 7 seconds, so a temperature deviation of around 10℃ may occur.

Experiment example 2. Measurement of manufacturability

The ease of the compounding process was measured when producing pellets using the polymer compositions in each Example and Comparative Example. If the compounding process takes less than 15 minutes, it is classified as ◎, if it takes more than 40 minutes, it is classified as △, and if it takes more than 60 minutes or the work is impossible, it is classified as X, and is shown in Table 1 below.

Table 1

Referring to Table 1, Example 1 was measured at a higher temperature range than Comparative Example 1. In Examples 1 to 5, a high temperature range was measured, showing that the polymer material of the present invention exhibits excellent reactivity to microwaves.

In addition, in Examples 6 and 7, the compounding process was either impossible or took a long time of more than 50 minutes. This shows that the excellent effects of the present invention can be achieved when the plasticizer compound and the hydroxy compound are used while supported on a porous carrier.

Claims (13)

delete delete delete delete delete delete delete delete Prepare a polymer composition containing 5 to 30 parts by weight of an additive that reacts exothermically with microwaves based on 100 parts by weight of ethylene vinyl acetate copolymer (EVA), which does not react exothermically with microwaves, and mix it with 100 parts by weight of the polymer composition. Preparing a mixed composition by adding 0.5 to 10 parts by weight of a foaming agent and stirring;
Producing pellets by dispersing and extruding the mixed composition;
Obtaining a bead-shaped foam by crosslinking the pellets;
Injecting the bead-shaped foam into a mold made of a material that does not react to microwaves and then heat-sealing the foam by irradiating it with a microwave at an output of 4 to 8 kw for 2 minutes or less;
It includes; obtaining a molded article by cooling the heat-sealed molded bead-shaped foam,
The additive is at least one of a plasticizer compound or an absorbent polymer,
The absorbent polymer is any one or more selected from the group consisting of polyacrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, and cellulose. A foam composition using a polymer composition moldable by microwave. Molding method.
According to clause 9,
A method of forming a foam composition using a polymer composition moldable by microwaves, characterized in that the bead-shaped foam expands without losing gas when irradiated with microwaves in the heat fusion molding step.
According to clause 9,
When the additive is a plasticizer-type compound, a method of forming a foam composition using a polymer composition moldable by microwaves, characterized in that the additive is included in a state supported on a porous material.
According to clause 9,
When the additive is an absorbent polymer, a method of forming a foam composition using a polymer composition moldable by microwaves, characterized in that the additive is included in a water-absorbed state.
According to clause 11,
The porous material is one or more selected from the group consisting of silica, alumina, niobium, tantalum, zirconium, carbon, magnesium, titanium, and polymer. Method of forming a foam composition using a polymer composition that can be molded by microwaves.