KR20150010238A - Non-halogen flame retardant foam and manufacturing method thereof - Google Patents

Abstract

The present invention relates to flame retardant foam using a flame retardant agent which does not include a halogen component and a method for producing flame retardant foam. The non-halogen flame retardant foam of the present invention is produced using a base plate mixture mixed with a basic resin consisting of any one of an ethylene-vinylacetate (EVA) copolymer resin and a polyolefin-based copolymer resin, a composition such as a foaming agent, a foaming assisting agent, a cross-linking agent, and the like, and a composite flame retardant agent mixed with an inorganic metal-based flame retardant agent and a phosphorous flame retardant agent. Moreover, in the non-halogen flame retardant foam and method for producing the same of the present invention, a Group 7 element which is a halogen material is not included so that human body harmfulness problems caused by a halogen material can be effectively solved. The composite flame retardant agent mixed with an inorganic metal-based flame retardant agent and a phosphorous flame retardant agent has excellent flame retardancy so that a problem in which foam that is an organic material easily ignites can be effectively solved. The composite flame retardant agent is mixed with the basic resin so that the original physical properties of completed foam are not inhibited.

Description

FIELD OF THE INVENTION The present invention relates to halogen-free flame-retardant foam,

The present invention relates to a method for producing a flame-retardant foam and a flame-retardant foam using a flame-retardant agent that does not contain a halogen component. More particularly, the present invention relates to a method for producing a flame- Flame retarding foam made by using a base plate mixture composed of a composition such as a foaming agent, a foaming aid, a crosslinking aid and the like and a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant.

The foamed foam having inherent characteristics of cushioning has advantages of cushioning function and is used for various purposes in real life or modern industry. Especially, it is widely used in shock absorbers or sealing materials for electronic products.

In recent years, as a result of development of flat panel displays or TSP (Touch Screen Panel) devices, foaming foam materials have been attracting attention as sealing materials and shock absorbers in order to prevent failure or damage of electronic products from moisture, dust or external impacts.

However, conventional foamed foam is easily dehydrated by heat generation of electronic products due to excessive heat or electric current overload which may occur in electronic products, and products with added flame retardancy are mainly used.

That is, in the case of the existing flame-retardant foam, a product obtained by adding a flame retardant using a cyclic element group 7 element (Br or Cl system) is mainly used, but in the case of the flame retardants having the group 7 element (Br, Cl) And the regulation movement is accelerated around the world.

In addition, due to the rapid development of information devices such as TVs, smart phones, notebooks, and tablet PCs, high-end parts are being applied to new products in the IT industry as a whole. As a result, high performance of CPUs or PCBs and mounting of AMOLED panels The heat is generated further, or the electric current is overloaded, and the rate of occurrence of fire in electronic products is further increased.

The following are representative conventional techniques for flame-retardant foam foam.

Korean Patent No. 10-0772289 discloses a flame retardant polyolefin crosslinked foam composition comprising 20 to 50% by weight of polypropylene, 20 to 50% by weight of recycled polyethylene, 0 to 10% by weight of ethylene-propylene copolymer, 10 to 20% by weight of polyethylene glycol maleic anhydride, and 0 to 10% by weight of polypropylene graft maleic anhydride. Wow; 2 to 5 parts by weight of a crosslinking agent, 10 to 15 parts by weight of a foaming agent, 0 to 2 parts by weight of a foaming auxiliary, 0 to 2.5 parts by weight of an internal blowing agent, 0 to 5 parts by weight of an external blowing agent, 0 to 10 parts by weight of a plasticizer, , 0 to 2.5 parts by weight of a heat transfer promoter, and 130 to 190 parts by weight of a flame retardant is added to 100 parts by weight of the resin.

In addition, the prior art of the above-mentioned constitution has improved the environment-friendliness, safety and mechanical properties, thereby making it possible to produce flame retardant and economical products with higher efficiency, and to achieve efficient recycling of waste resources. However, , It is difficult to expect the process stability due to the too high composition ratio of the flame retardant composed mainly of polyolefin, and it is impossible to implement the flame retardancy which satisfies the UL94 HBF, UL94HF-1,2 flammability specification, It is required to continue research and development.

TECHNICAL FIELD The present invention relates to a foamed foam used as a shock absorber or sealing material for electronic products such as TVs, smart phones, notebooks, and tablet PCs using a flat panel display or a TSP (Touch Screen Panel) , A conventional foamed foam mainly used a halogen-based flame retardant containing a cyclic element group 7 element (Br-based, Cl-based), causing a harmful problem to the human body;

When a flame retardant with insufficient flame retardancy is used, a foaming foam (shock absorber or sealing material), which is an organic substance, may easily be ignited when an electric product generates heat due to excessive heat or current overload that may occur in the electronic product ;

In the case of producing a foamed foam using a general flame retardant containing a cyclic element group 7 element, in order to satisfy a certain flame retardancy, an excessive flame retardant is added to the base resin of the foamed foam, such as an ethylene-vinyl acetate (EVA) copolymer resin or a polyolefin- It is difficult to produce a foamed foam of good quality due to an excessive amount of the composition of the flame retardant and the manufacturing process of the foamed foam is not smooth due to the composition ratio of the excessive flame retardant. And a solution to this problem is provided.

The present invention has been made to solve the above-

2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a crosslinking agent (or 0.1 to 5 parts by weight of a foaming auxiliary agent (hereinafter referred to simply as " foaming aid agent ") is added to 100 parts by weight of a base resin constituted of any one of ethylene / vinyl acetate (EVA) copolymer resin and polyolefin copolymer resin And 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant are extruded into a base plate, chemically crosslinked (or electron beam crosslinked), foamed as a foam furnace, A halogen-free flame retardant foam foam that is configured to be made;

2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a crosslinking agent (or 0.1 to 5 parts by weight of a foaming auxiliary agent (hereinafter referred to simply as " foaming aid agent ") is added to 100 parts by weight of a base resin constituted of any one of ethylene / vinyl acetate (EVA) copolymer resin and polyolefin copolymer resin 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant; An extrusion step of extruding the base plate prepared in the mixture preparation step into a base plate having a certain width and thickness by using an extruder having a cylinder and a die temperature of 90 to 210 ° C; A cross-linking / foaming step (or an electron beam cross-linking step and a foaming step) in which the base extruded by the extrusion processing process is chemically cross-linked as a cross-linking agent included in the mixture preparation step in a foaming furnace at 140 to 300 ° C and decomposed and foamed; Halogen flame retardant foamed foam comprising the above composition.

Since the halogen-free flame-retarded foam according to the present invention and the method of manufacturing the same according to the present invention do not include a periodic element group 7 element, which is a halogen substance, the effect of solving the harmfulness problem of a human body due to a halogen substance can be obtained;

An excellent flame retardancy of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant makes it possible to obtain an effect of solving the problem that an organic foam foam is easily ignited;

In order to satisfy the constant flame retardancy, a general flame retardant is excessively mixed in an ethylene-vinyl acetate (EVA) copolymer resin or a polyolefin-based copolymer resin as a base resin to solve the problem that the manufacturing process of the foamed foam is not smooth ≪ / RTI >

It is possible to obtain an effect that the composite flame retardant is mixed with the base resin so that the inherent physical properties of the foamed foam produced are not hindered.

1 (a) to 1 (b) are block diagrams showing a method for producing a halogen-free flame-retardant foam according to a preferred embodiment of the present invention.
2 is a flame resistance test report of a halogen-free flame retardant foam according to Test Example 1 of the first preferred embodiment of the present invention.
3 (a) to 3 (e) are test results related to harmful substances (halogen compounds) of a halogen-free flame-retardant foam according to Test Example 1 of the first preferred embodiment of the present invention.

The present invention relates to a method for producing a flame-retardant foam and a flame-retardant foam using a flame-retardant agent that does not contain a halogen component. More particularly, the present invention relates to a method for producing a base resin 100 And 15 to 85 parts by weight of a composite flame retardant obtained by mixing 2 to 40 parts by weight of a blowing agent, 0.1 to 5 parts by weight of a crosslinking agent (or 0.1 to 5 parts by weight of a foaming aid) and an inorganic flame retardant with a phosphorus flame retardant, Flame retarded foamed foam which is configured such that the matrix mixture is extruded into a matrix, chemically crosslinked (or electron beam crosslinked), and foamed as a foam furnace to be made into a foam;

2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a crosslinking agent (or 0.1 to 5 parts by weight of a foaming auxiliary agent (hereinafter referred to simply as " foaming aid agent ") is added to 100 parts by weight of a base resin constituted of any one of ethylene / vinyl acetate (EVA) copolymer resin and polyolefin copolymer resin 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant; An extrusion step (S200) of extruding the base plate prepared in the mixture preparing step (S100) into a base plate having a certain width and thickness using an extruder having a cylinder and a die temperature of 90 to 210 DEG C;

(Step S300) in which the base plate extruded by the extrusion step (S200) is chemically cross-linked as a cross-linking agent included in the mixture preparation step (S100) in a foaming furnace at 140 to 300 deg. C and the foaming agent is decomposed and foamed Or an electron beam cross-linking step (S300 ') and a foaming step (S300 ")).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to FIGS. 1 to 3 showing embodiments of the present invention.

First, the present invention is characterized in that 2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a crosslinking agent (or 0.1 to 5 parts by weight of a foaming auxiliary) is added to 100 parts by weight of a base resin composed of any one of EVA copolymer resin and polyolefin- And 15 to 85 parts by weight of a composite flame retardant comprising a mixture of an inorganic metal flame retardant and a phosphorus flame retardant. The mixture preparation step (S100), the extrusion step (S200) for preparing the flame retardant foam ), A crosslinking / foaming step (S300) (or an electron beam crosslinking step (S300 ') and a foaming step (S300)).

In the method for producing a flame-retarding foamed foam, a chemical crosslinking method using a crosslinking agent and an electron beam crosslinking method using an electron beam are shown in Examples 1 and 2 described below.

- I halogen  Flammability Foam foam  And a method for producing the same (chemical crosslinking) -

Specifically, the matrix mixture of the present invention is a mixture of compositions constituting a base matrix, which is a matrix for forming a foamed foam, in which a base resin, a foaming agent, a crosslinking agent and a composite flame retardant are mixed.

That is, the base resin is a thermoplastic synthetic resin composed of any one of an ethylene-vinyl acetate (EVA) copolymer resin and a polyolefin-based copolymer resin, and the base resin of this kind is widely known as a main component of a foamed foam, have.

When a polyethylene-based copolymer resin is used as a base resin in the polyolefin-based copolymer resin, HDPE (high density polyethylene) or LDPE (low density polyethylene) can be used. In order to obtain a desired expansion ratio of the matrix mixture, HDPE It is preferable to use LDPE having a smaller density.

The foaming agent may be any kind of foaming agent capable of foaming a base resin such as an ethylene-vinyl acetate (EVA) copolymer resin or a polyolefin-based copolymer resin, but may be any one selected from the group consisting of ammonium hydrogencarbonate, sodium hydrogencarbonate, Sodium or the like, or an organic foaming agent such as azodicarbonamide, dinitrosopentamethylenetetramine, benzenesulfonylhydrazide, toluenesulfonylhydrazide, toluenesulfonylsemicarbazide, etc. may be used .

In addition, since the foaming agent of this kind has a certain chemical stability with respect to thermal energy, it is difficult to dissolve (foam) the premix mixture containing the foaming agent prematurely during the extrusion process (S200) in which high temperature (90 to 210 DEG C in the present invention) So that it is possible to prevent the production of defective flame-retarded foamed foam.

When the composition ratio of the blowing agent is less than 2 parts by weight based on 100 parts by weight of the base resin, the expansion ratio of the flame-retardant foam foam is lowered, and the foam foam having a hard texture is produced. Thus, the foam foam functions smoothly to feel a certain cushioning feeling If the content of the flame retardant foam is more than 40 parts by weight, the respective compositions are not smoothly dispersed and mixed at the time of mixing the compositions constituting the base plate mixture, and the expansion ratio of the finished flame retardant foam foam becomes excessively high, It is preferable to maintain the composition ratio of 2 to 40 parts by weight with respect to 100 parts by weight of the base resin because there is a possibility that the flame retardancy is deteriorated and the physical strength is lowered.

When the base resin of the base plate mixture is a polypropylene type copolymer resin, the base plate mixture contains a cadmium compound, a calcium compound ( and 0.1 to 5 parts by weight of a foaming aid such as a cesium compound, a zinc compound, a magnesium compound, an iron compound or a copper compound.

That is, the polypropylene-based copolymer resin that can be used as a base resin of the matrix mixture further contains carbon as compared with the polyethylene-based copolymer resin, and can be used as the above-mentioned foaming agent, In order to add the effect of adjusting the expansion ratio of the base plate and the effect of controlling the expansion temperature of the base plate (activation of the foaming agent) during the following foaming step (S300 ") in addition to the foaming agent, It is possible to further include a foaming aid.

At this time, it is preferable that the composition ratio of the foaming aid is not more than 5 parts by weight relative to 100 parts by weight of the polypropylene-based copolymer resin so that the base resin is not foamed in the extrusion step (S200) in which the foaming agent is excessively activated and the base sheet is molded.

In addition, the crosslinking agent is obtained by separating some of the hydrogen bonded to the carbon constituting the base resin (EVA copolymer resin or polyolefin copolymer resin), separating hydrogen from the partially separated polyethylene-based resin polymer (polymer or EVA copolymer (Dicumyl peroxide), diacyl peroxide, peroxyketal, and the like may be used as long as they are capable of performing the function of crosslinking the resin , An organic peroxide such as peroxy ester, peroxycarbonate or ketone peroxide, an unsaturated resin crosslinking agent such as a vinyl monomer, an acrylic compound, a methacrylic compound or an epoxy compound, or a polyurethane crosslinking agent.

The cross-linking agent having the above-described structure not only exhibits a macroscopic effect of reinforcing heat resistance through long-term cross-linking between chains of the polyolefin-based copolymer resin polymer (or EVA copolymer resin polymer) ), The extrusion process (S200) is a constitution for controlling an appropriate viscosity of the matrix mixture to be treated.

When the composition ratio of the cross-linking agent is less than 0.1 part by weight based on 100 parts by weight of the base resin, the heat resistance of the finished flame-retardant foam is inferior because the degree of crosslinking is insufficient, or the extrusion step (S200) If the amount exceeds 5 parts by weight, the viscosity of the base plate treated in the extrusion step (S200) may be too high to raise the productivity. Therefore, when 100 parts by weight of the base resin , It is preferable to maintain the composition ratio of 0.1 to 5 parts by weight.

Further, in the case where the base resin of the matrix mixture is a polypropylene-based copolymer resin, the present invention may further comprise a crosslinking aid. That is, since the polypropylene-based copolymer resin has a structure that further contains carbon as compared with the polyethylene-based copolymer resin, and since chemical crosslinking may not be easy with only the crosslinking agent, triallylisocyanurate Triallylisocyanuate, trimethylolpropane trimethacrylate, or metallic ionomer may be added in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the polypropylene-based copolymer resin . If the composition ratio of the crosslinking aid is less than 0.1 part by weight, the effect of the crosslinking aid is insufficient, and if the amount exceeds 5 parts by weight, the content of the crosslinking aid is excessively passed, and the crosslinking agent is activated in the extrusion step (S200) It is preferable to further include 0.1 to 5 parts by weight based on 100 parts by weight of the polypropylene-based copolymer resin.

The composite flame retardant is composed of an inorganic metal flame retardant mixed with an inorganic flame retardant and a phosphorus flame retardant. The inorganic flame retardant has a flame retardant effect mainly due to dehydration reaction. The flame retardant is a flame retardant The effect of mixing and complementary flame retarding action can be realized and the composition ratio of the flame retardant to the base resin can be suitably maintained (not high), thereby making it possible to smooth the production process of the foam foam, Can be excellently maintained.

That is, in general, the flame retardant is one of the functional compounds added to the polymer compound, which improves the properties of the compound which is likely to be burned to prevent burning, and reduces the toxic gas and toxicity generated during combustion, It is an additive that improves the functionality. The flame retardant is classified into an organic flame retardant and an inorganic flame retardant depending on the constituent components. The organic flame retardant is classified into phosphorus, nitrogen, and halogen (bromine and chlorine).

In connection with the above, the halogen flame retardant acts as a flame retardant by capturing radicals in the gas phase, and the generated halogen gas may corrode metals such as molds and electric wires to cause a serious impact on the base polymer or the manufacturing equipment It is also harmful to human body. Therefore, in the prior art, a halogen-based flame retardant such as calcium stearate or hydrotalcite compound (DHT-4A, Kyowa), an antimony flame retardant, zinc borate zinc borate or phosphorus flame retardant.

That is, in order to improve the ease of manufacture of the product, the stability of the manufacturing equipment, and the flame retardancy, the conventional flame retardant has been mixed with other components, and most of the flame retardants are harmful to the human body. In particular, a flame retardant mixed with a halogen-based flame retardant or a phosphorus flame retardant and a halogen-based flame retardant is mainly used in the technical field of flame-retardant foamed foams.

Specifically, the composite flame retardant according to the present invention is composed of an inorganic flame retardant containing an inorganic metal and an organic flame retardant mixed with a phosphorus flame retardant among the inorganic flame retardants. At this time, the inorganic metal-based flame retardant can be generally known one, but it is preferable to use at least one of aluminum hydroxide, antimony trioxide, antimony pentoxide, magnesium hydroxide, zinc stearate, molybdic acid or zirconium.

Particularly, aluminum hydroxide and magnesium hydroxide, which are metal hydroxide compounds, are flame retardants that suppress the combustion phenomenon by depriving the combustion point of combustion while suppressing the combustion gas. H ₂ O is generated during combustion and dilutes the combustible gas while changing into steam. To reduce the combustion temperature.

The phosphorus flame retardant may be a generally known flame retardant, but it is preferable to use at least one of ammonium phosphate, ammonium polyphosphate, metal phosphinate, and melamine polyphosphate.

That is, the phosphorus flame retardant reacts with the combustible material in the combustion process to form a carbonaceous layer on the polymer surface, and this carbonization layer blocks the oxygen required for the combustion and exhibits a flame retarding effect. Specifically, the phosphorus-based flame retardant generates phosphoric acid and polyphosphoric acid by pyrolysis, wherein the phosphoric acid and polyphosphoric acid produced form a char by esterification and dehydration reaction, and the char interferes with oxygen and heat, I will exert. In addition, phosphate decomposes to produce radicals such as HPO ₂ and PO, which stabilize the active radicals OH and H.

Further, as described above, the composite flame retardant according to the present invention exerts the effect of realizing the flame retardancy and the functionality of the inorganic flame retardant and the phosphorus flame retardant in a complex manner, and particularly, in the production of flame retardant foam, It has an excellent flame retardancy within a range not to be inhibited and also has an effect of solving the problem of a normal manufacturing process which can be caused by using an inorganic metal flame retardant or a phosphorus flame retardant alone.

That is, when the inorganic metal-based flame retardant is used alone in the base plate mixture, in order to realize the same flame retardancy, it is necessary to use an inorganic metal flame retardant The density is excessively high and the feeling of cushioning deteriorates. In the extrusion process (S200) in which the extrusion-molding of the extrusion-molded base plate mixture is carried out as a base plate, the exact cause is unknown. However, The cells of the foamed foam formed by the thermal energy are smoothly and uniformly dispersed in the crosslinking and foaming step S300 (particularly the foaming step S300 ") after the extrusion step S200, A problem that can not be formed occurs.

Also, when the phosphorus flame retardant is used alone in the base plate mixture, the exact cause is unknown in the extrusion process (S200) in which the base plate mixture is extruded into a base plate as an extruder, but the phosphorus flame retardant agent and the foaming agent interact, A cell of a foamed foam formed by heat energy is smoothly formed during a crosslinking and foaming step (S300) (particularly a foaming step (S300 ")) in which the foaming process is performed after the extrusion step (S200) The problem that can not be solved occurs.

In addition, it is preferable that the composite flame retardant of the present invention is mixed with the matrix mixture at a composition ratio of 15 to 85 parts by weight based on 100 parts by weight of the base resin. When the composite flame retardant is mixed in an amount of less than 15 parts by weight, there arises a problem that flame retardancy of the foamed foam is insufficient. When the composite flame retardant exceeds 85 parts by weight, the tensile strength or compressive strength of the foamed foam is lowered, The density becomes too high and the compression hardness associated with the cushion feeling becomes too high. Therefore, it is desirable to maintain the composition ratio within the above range.

The composition ratio of the inorganic metal-based flame retardant and the phosphorus-based flame retardant constituting the composite flame retardant can be appropriately adjusted so that the composition ratio of the inorganic metal flame retardant and the phosphorus flame retardant do not excessively deviate to either one of the compositions, 50 to 80% by weight of an inorganic metal-based flame retardant and 20 to 50% by weight of a phosphorus-based flame retardant.

That is, when the composition ratio of the inorganic metal-based flame retardant contained in the composite flame retardant is less than 50% by weight, the phosphorus-containing flame retardant is relatively excessively contained and the foam in the foaming step (S300) If the composition ratio of the inorganic metal-based flame retardant exceeds 80% by weight, early decomposition of the foaming agent occurs during the extrusion step (S200) and the stability of the extrusion step (S200) can not be maintained. Since the specific gravity of the extruded sheet is increased due to the inorganic metal-based flame retardant having a high specific gravity contained in the composite flame retardant in the step (S300 "), the resin specific gravity in the extruded sheet mixture is lowered and the proper viscoelasticity through crosslinking can not be given. It is impossible to expect a stable quality as much as possible and it is impossible to maintain a constant level of flame retardancy, To maintain the preferred.

The matrix mixture of the present invention may further comprise 0.1 to 5 parts by weight of a coupling agent per 100 parts by weight of the base resin. At this time, the coupling agent is a structure for facilitating the mixing (kneading) between the base resin and the composite flame retardant contained in the matrix mixture.

That is, before the extrusion step (S200), each composition is extrusion-molded in the form of a base plate by an extruder while being mixed with the composition ratio according to the present invention. However, the composite flame retardant according to the present invention composed of an inorganic metal flame retardant and a phosphorus flame retardant is a polar material having a polarity due to the electrical state of the molecule, and since the base resin is a non-polar material having a non-polarity, There is a concern that it may take a long time. At this time, the coupling agent alleviates the polarity of the composite flame retardant, realizing the effect that the composite flame retardant can be uniformly dispersed and mixed in the base resin.

At this time, the coupling agent may be any of Si-based, zirconium-based, aluminum-based or Ti-based. If the composition ratio of the coupling agent is less than 0.1 part by weight with respect to 100 parts by weight of the base resin, there is a problem that the dispersion and mixing property by the coupling agent is insufficient. When the amount is more than 5 parts by weight, The physical properties of the foamed foam that has been manufactured are lowered. Therefore, it is preferable to maintain the composition ratio within the above range.

In connection with the above, the present invention is capable of a configuration that further includes a lubricant in the coupling agent. That is, the lubricant is at least one of a polyolefin, a montanic acid and a stearic acid, and is contained in a base plate mixture together with a coupling agent. When the base plate mixture is extruded in a cylinder of an extruder and discharged into a base plate, To thereby prevent the foaming agent contained in the base plate mixture from prematurely foaming (prematurely decomposing).

At this time, the composition ratio of the lubricant included in the coupling agent can be adjusted appropriately according to the judgment of a person skilled in the art, but it is preferable to maintain the composition ratio within the range of 0.1 to 5 wt% with respect to the total weight of the coupling agent included in the base plate mixture.

A preferred method for producing the halogen-free flame retardant foam according to the present invention is as follows.

That is, the present invention relates to a resin composition comprising 2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a crosslinking agent, and 0.1 to 5 parts by weight of a crosslinking agent, based on 100 parts by weight of a base resin composed of any one of an ethylene-vinyl acetate (EVA) copolymer resin and a polyolefin- 15 to 85 parts by weight of a composite flame retardant mixed with a metal-based flame retardant and a phosphorus-based flame retardant; An extrusion step (S200) of extruding the base plate prepared in the mixture preparing step (S100) into a base plate having a certain width and thickness using an extruder having a cylinder and a die temperature of 90 to 210 DEG C; (S300) of chemically crosslinking the base plate extruded by the extrusion process (S200) as a crosslinking agent included in the mixture preparation process (S100), and foaming it as a foaming furnace at 140 to 300 deg. do.

Specifically, the mixture preparation step (S100) may include a step of preparing a base resin, a foaming agent, a cross-linking agent, and a composite flame retardant (or a coupling agent, a foam auxiliary agent, A crosslinking aid, etc.), which is a process of mixing the respective compositions of the matrix mixture specifically described above by a general method.

At this time, the composite flame retardant may be mixed with other compositions of the flock mixture after the inorganic flame retardant and the phosphorus flame retardant are first mixed before being mixed with other compositions of the flock mixture.

Hereinafter, a detailed description of the compositions to be mixed in the mixture preparation step (SlOO) will be substituted for the above description.

Further, the extrusion step (S200) is a step of extruding the base plate prepared in the mixture preparation step (S100) into a base plate having a certain width and thickness by using an extruder having a cylinder and a die temperature of 90 to 210 DEG C, A single screw extruder or a twin screw extruder is used to process the foams by using a separate screw to feed the foaming agent in a side feeding manner to further prevent premature foaming due to the foaming agent. A kneader mixture is kneaded and extruded as an extruder having a screw, a cylinder having a temperature of 90 to 210 DEG C and a die having a temperature of 90 to 210 DEG C.

When the temperature of the cylinder and the die is lower than 90 ° C, the base resin is slightly melted and the kneadability of the base plate mixture is lowered. When the temperature exceeds 210 ° C, It is preferable to maintain the temperature of the cylinder and the die of the extruder at 90 to 210 DEG C because the problem of cross-linking the matrix mixture to be crosslinked prematurely occurs.

The crosslinking and foaming step (S300) is a step of chemically crosslinking the base plate extruded by the above-mentioned extrusion step (S200) as a crosslinking agent included in the mixture preparing step (S100), and foaming it as a foaming furnace at 140 to 300 DEG C, It is preferable to use a foaming furnace capable of treating hot air having a temperature of 140 to 300 DEG C and an air velocity of 10 to 50 Hz. When the temperature inside the foaming furnace is lower than 140 캜, the crosslinking agent contained in the base plate mixture is slightly activated so that the polyolefin-based copolymer, which is the main component of the base plate mixture, It is difficult to induce long-term crosslinking between the resin polymer (or EVA copolymer resin polymer) chain and the viscosity of the base plate crosslinked and foamed at the crosslinking and foaming step (S300) If the temperature inside the foaming furnace exceeds 300 ° C., the surface of the base plate is deteriorated due to excessive heat, and it is difficult to produce a high-quality flame-retardant foam. Therefore, the temperature of 140 to 300 ° C. is maintained . Also, it is preferable that the speed of the hot air applied to the base plate has a wind speed of 10 to 50 Hz so that the surface of the flame-retardant foam foam and the inner foam shape can be manufactured with good quality.

[ Test Example  One]

1. Mixture preparation process

- 55.6 kg of LDPE (L), 15.0 kg of azodicarbonamide (100% conversion standard), 0.5 kg of dialkyl-aryl peroxide (based on 100%), magnesium hydroxide 20.0 kg, melamine polyphosphate kg and an aluminum-based coupling agent (P company) (1.1 kg) are mixed to prepare a base plate mixture.

2. Extrusion process

-The base plate prepared in 1. above was fed into a single screw extruder (screw rotating speed, 28 rpm) preheated at a cylinder and a die temperature of 100 캜 to extrude a base plate having a length × width × thickness of 200 m × 500 mm × 1.7 mm .

3. Cross-linking and foaming process

- Using a horizontal foaming furnace preheated at a temperature of 200 ° C and a wind speed of 20 hz, the base extruded in the above step 2 was charged at a rate of 4 m / min and subjected to crosslinking and foaming to obtain a crosslinking degree of 50% A flame-retardant foam is prepared and taken at a speed of 12 m / min.

[ Comparative Example  1-1]

1. Mixture preparation process

24.5 kg of LDPE (L), 15.0 kg of azodicarbonamide (100% conversion standard), 0.5 kg of dialkyl-aryl peroxide (based on 100%) and 60.0 kg of magnesium hydroxide were mixed to prepare a base plate mixture.

2. Extrusion process

-The base plate prepared in 1. above was fed into a single screw extruder (screw rotating speed, 28 rpm) preheated at a cylinder and a die temperature of 100 캜 to extrude a base plate having a length × width × thickness of 200 m × 500 mm × 1.7 mm .

3. Cross-linking and foaming process

- Using a horizontal foaming furnace preheated at a temperature of 200 ° C and a wind speed of 20 hz, the base extruded in the above step 2 was charged at a rate of 4 m / min and subjected to crosslinking and foaming to obtain a crosslinking degree of 50% A flame-retardant foam is prepared and taken at a speed of 12 m / min.

[ Comparative Example  1-2]

1. Mixture preparation process

64.5 kg of LDPE (L), 15.0 kg of azodicarbonamide (100% conversion standard), 0.5 kg of dialkyl-aryl peroxide (based on 100% conversion) and 20.0 kg of a base plate.

2. Extrusion process

-The base plate prepared in 1. above was fed into a single screw extruder (screw rotating speed, 28 rpm) preheated at a cylinder and a die temperature of 100 캜 to extrude a base plate having a length × width × thickness of 200 m × 500 mm × 1.7 mm .

3. Cross-linking and foaming process

- Using a horizontal foaming furnace preheated at a temperature of 220 ° C and a wind speed of 20 hz, the base extruded in the above step 2 was charged at a rate of 4 m / min and subjected to crosslinking and foaming to obtain a crosslinking degree of 50% and a foaming magnification of 30 times A flame-retardant foam is prepared and taken at a speed of 12 m / min.

[ Comparative Example  1-3]

1. Mixture preparation process

- 74.5 kg of LDPE (L), 15.0 kg of azodicarbonamide (100% conversion standard), 0.5 kg of dialkyl-aryl peroxide (based on 100%), 7.5 kg of DBDPO and 2.5 kg of Sb ₂ O ₃ Prepare a matrix mixture.

2. Extrusion process

-The base plate prepared in 1. above was fed into a single screw extruder (screw rotating speed, 28 rpm) preheated at a cylinder and a die temperature of 100 캜 to extrude a base plate having a length × width × thickness of 200 m × 500 mm × 1.7 mm .

3. Cross-linking and foaming process

- Using a horizontal foaming furnace preheated at a temperature of 220 ° C and a wind speed of 20 hz, the base extruded in the above step 2 was charged at a rate of 4 m / min and subjected to crosslinking and foaming to obtain a crosslinking degree of 50% and a foaming magnification of 30 times A flame-retardant foam is prepared and taken at a speed of 12 m / min.

[Test]

Five test specimens were obtained from the flame-retardant foam prepared by the method of Test Example 1 and Comparative Examples 1-1 to 1-3, respectively. Then, according to the test method using UL94HF-1, the residual time, the remaining time, And the ignition of the indicator cotton were tested, and the results as shown in Table 1 below were obtained.

[result]

As shown in Table 1, the flame retarding foam prepared according to Test Example 1 of the present invention had good process stability even during the extrusion process and the foaming process, and had a relatively high density compared with Comparative Examples 1-1 and 1-2 , It can be seen that the cushion feeling is more excellent and it is found that both the flushing time, the residual time, the carbonization up to the mark of 60 mm and the ignition of the indicator cotton are all suitable, and the detection accuracy of the halogen substance .

On the other hand, in Comparative Example 1-1 (only the inorganic metal flame retardant is used as a flame retardant) and Comparative Example 1-2 (only phosphorus flame retardant is used as a flame retardant), the process stability in the extrusion process and the foaming process is poor , The density is higher than that of Test Example 1, the cushion feeling is less, and the degree of detection of the halogen substance (regulated substance) is also suitable, but the flame retardancy indicating that the flame retardant time, the remaining time, the carbonization to the 60 mm marking line, Able to know.

In addition, the foamed foam according to Comparative Example 1-3, in which a halogen-based flame retardant and an inorganic flame retardant (antimony trioxide) are used as flame retardants, has a good process stability in the extrusion process and the foaming process, has a density similar to that of Test Example 1, However, there is a problem that a large amount of bromine, which is a regulated substance, is detected.

- I halogen  Flammability Foam foam  And a method for producing the same (electron beam crosslinking)

The present invention provides an electron beam crosslinking method using an electron beam as a crosslinking method of other halogen-free flame-retardant foamed foams which can produce an unburned halogen-flame-retarded foamed foam through a chemical crosslinking method as in the case of Example 1 above. Hereinafter, among the specific explanations related to the second embodiment, the description overlapping with the first embodiment will be replaced with the detailed description of the first embodiment.

The non-halogen flame retarding foam according to the second embodiment and the method for producing the same according to the second embodiment are different from those of the first embodiment in that some compositions of the matrix mixture of the mixture preparation step (SlOO) are made differently and macroscopically performed after the extrusion step (S200) The crosslinking / foaming step (S300) is divided into the electron beam crosslinking step (S300 ') and the foaming step (S300).

Specifically, the present invention relates to a resin composition comprising 2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a foaming aid, and 0.1 to 5 parts by weight of a foaming agent, based on 100 parts by weight of a base resin composed of any one of an ethylene-vinyl acetate (EVA) copolymer resin and a polyolefin- , 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant, extruded into a base plate, irradiated with an electron beam to crosslink the base plate, and foamed as a foam furnace to be made into a foam .

That is, the base resin and the foaming agent have the same constitution as that of Embodiment 1, and a configuration including the foaming assistant differently from Embodiment 1 is adopted. Further, the description of the basic resin and the foaming agent will be replaced by the description of the first embodiment. On the other hand, the foaming aid is used in combination with a foaming agent for cadmium compound, calsium compound, zinc (zinc) for controlling the expansion ratio of the matrix in the foaming step (S300 ") and controlling the foaming temperature It is preferable that 0.1 to 5 parts by weight of a foaming aid of an inorganic compound such as a zinc compound, a magnesium compound, an iron compound or a copper compound is contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the base resin desirable.

If the content of the foaming auxiliary is less than 0.1 part by weight, the function of the foaming auxiliary agent is difficult to exhibit smoothly due to insufficient mixing ratio. If the content of the foaming auxiliary agent is more than 5 parts by weight, the foaming agent induces premature decomposition in the extruder, It is desirable to maintain the above content ratio because the appearance defects, physical strength and flame retardancy of the finished flame-retarded foam foam may deteriorate.

When the base resin is composed of EVA copolymer resin or polyolefin-based copolymer resin resin, the base resin mixture may contain 100 parts by weight of a base resin composed of EVA copolymer resin or polyolefin-based copolymer resin 0.1 to 5 parts by weight of a crosslinking aid such as triallylisocyanuate, trimethylolpropane trimethacrylate or a metallic ionomer may be further added to the resin composition. That is, the EVA copolymer resin or the polypropylene-based copolymer resin may further include the above-mentioned crosslinking aid which can facilitate the activity of the crosslinking agent, since the crosslinking agent alone may not facilitate electron beam crosslinking.

If the amount of the crosslinking aid is less than 0.1 parts by weight based on 100 parts by weight of the EVA copolymer resin or the polyolefin copolymer resin, the effect of the crosslinking aid is insufficient and the proper viscoelasticity If the amount exceeds 5 parts by weight, the content of the cross-linking auxiliary agent is excessively increased, and the viscoelasticity of the extruded sheet becomes sharply increased, so that there is a possibility that a foam having good quality (cell breakage, void) can not be produced at the time of foaming Therefore, it is preferable that 0.1 to 5 parts by weight is further added to 100 parts by weight of the EVA copolymer resin or the polypropylene-based copolymer resin.

The base plate mixture may further comprise, as in Example 1, 0.1 to 5 parts by weight of a coupling agent per 100 parts by weight of the base resin.

The composite flame retardant of the matrix mix is also prepared by mixing the inorganic metal flame retardant and the phosphorus flame retardant in a constant composition ratio, and the composition is contained in the matrix mixture in an amount of 15 to 85 parts by weight based on 100 parts by weight of the base resin. do. In addition, the composite flame retardant may include 50 to 80% by weight of an inorganic metal-based flame retardant and 20 to 50% by weight of a phosphorus-based flame retardant, as in Example 1.

Hereinafter, the description of the coupling agent and the composite flame retardant will be replaced by the description of the first embodiment.

In addition, a preferable method for producing the halogen-free flame-retardant foam of the present invention by the electron beam crosslinking method is as follows.

That is, the present invention relates to a resin composition comprising 2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a foaming auxiliary agent, and 0.1 to 5 parts by weight of a foaming agent, based on 100 parts by weight of a base resin constituted by any one of ethylene-vinyl acetate (EVA) copolymer resin and polyolefin- 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant; An extrusion step (S200) of extruding the base plate prepared in the mixture preparing step (S100) into a base plate having a certain width and thickness using an extruder having a cylinder and a die temperature of 90 to 210 DEG C; An electron beam cross-linking step (S300 ') of irradiating a base plate extruded by the extrusion step (S200) with an electron beam having a voltage of 100 to 1500 kv and an electron dose of 0.1 to 5.0 Mrad to bridge the base plate; And a foaming step (S300 ") for foaming the base plate treated with the electron beam crosslinking step (S300 ') at a temperature of 140 to 300 DEG C as a foaming furnace.

Specifically, the mixture preparation step (S100) may include a step of mixing the base resin, the foaming agent, the foam auxiliary agent, and the composite flame retardant (or the coupling agent, the crosslinking auxiliary agent) composed of any one of the ethylene-vinyl acetate (EVA) copolymer resin and the polyolefin- (S100) of Embodiment 1, except that the composition of the base plate mixture is somewhat different from that of the base plate preparation process of Embodiment 1 (S100). Since only the kind of the composition constituting the matrix mixture is different and the processing method is the same, a detailed description of the mixture preparation step (S100) will be replaced with the description related to the first embodiment.

As described above, the base plate mixture prepared as the mixture preparation step (S100) is subjected to an extrusion process (S200) for extrusion molding with a base plate having a certain width and thickness. The present process is carried out as an extruder having the same constitution as that of Example 1. The main point of this process is that the temperature of the cylinder and the dice constituting the extruder is preferably 90 to 210 캜. Specifically, the extrusion step (S200) exerts the effect of uniformly mixing the entire composition contained in the base plate mixture prepared in the mixture preparation step (S100). At this time, the temperature range of the cylinder and the dice constituting the extruder also has the same purpose as the first embodiment.

As described above, the base plate having a predetermined width and thickness processed by the extrusion process (S200) performs an electron beam cross-linking process (S300 ') for crossing the base plate by irradiating an electron beam having a predetermined voltage and a predetermined electron dose. Specifically, the crosslinking of the flame-retardant foam using an electron beam (the same concept as that of the basic resin crosslinking or matrix crosslinking as the main component) is carried out using a polyolefin-based copolymer resin (or EVA copolymer resin, hereinafter also referred to as " polyolefin- ) Is irradiated with an accelerated electron beam to remove hydrogen from a chain of the polyolefin-based copolymer resin to produce a polyolefin-based copolymer resin radical, and induction of crosslinking between chains of the polyolefin-based copolymer resin by the produced radical Method.

At this time, since the polyolefin-based copolymer resin generally has similar chemical properties, the crosslinking voltage or the crosslinking electron dose to be applied at the time of electron beam crosslinking can be performed in the same manner regardless of the type of the polyolefin-based copolymer resin. However, the strength of the crosslinking voltage is maintained at 100 to 1500 kv according to the thickness of the extrusion-molded base plate in the extrusion step (S200), so that proper crosslinking can be established between the polyolefin-based copolymer resin chains, and the crosslinked electron dose is included in the base plate mixture It is preferable to keep it at 0.1 to 5.0 Mrad depending on the density and physical properties of the blowing agent.

That is, when the cross-linking voltage is less than 100 kV, if the thickness of the base plate is too thick, the electron beam can not penetrate into the base plate and the inside of the base plate can not be crosslinked. If the cross-linking voltage exceeds 1500 kV, It is preferable to apply a crosslinking voltage of 100 to 1500 kv because the electron beam overlaps and over-crosslinking reaction occurs and flame retardant foam of desired expansion ratio can not be obtained in the foaming step (S300 "). It is preferable to maintain 0.1 to 5.0 Mrad.

Further, the foaming step (S300 ") of the present invention is a process for constituting a cushioning feeling on the base plate by decomposing the base plate treated in the electron beam crosslinking step (S300 ') in the foaming furnace included in the mixture preparing step (S100) The same step as the crosslinking / foaming step (S300) of Example 1 is carried out. At this time, in the foaming step (S300 ") of Embodiment 2, since the base plate does not contain a crosslinking agent for inducing chemical crosslinking, It will be appreciated by those skilled in the art.

[ Test Example  2]

1. Mixture preparation process

, 7.0 kg of azodicarbonamide (based on 100% conversion), 1.0 kg of zinc stearate (Zn-st), 20.0 kg of magnesium hydroxide, 5.0 kg of melamine polyphosphate And 1.1 kg of a coupling agent (P company) are mixed to prepare a base plate mixture.

2. Extrusion process

-The base plate prepared in 1. above was fed into a twin-screw extruder (screw rotational speed, 20 rpm) preheated at a temperature of cylinder and dice of 140 ° C at a feed rate of 120 kg / hr to prepare a sheet having a length × width × thickness of 200 m × 670 mm × A base plate having a thickness of 0.5 mm is extrusion-molded.

3. Electron Beam Bridging Process

-The base plate extruded in 2. above is charged and pulled at a speed of 30 m / min to an electron beam crosslinking apparatus having a voltage of 500 kV and an electron dose of 2Mard to prepare a base plate having a crosslinking degree of 50%.

4. Foaming Process

- A flask subjected to cross-linking treatment in step 4 was charged at a rate of 9 m / min using a foam furnace preheated to a temperature of 250 DEG C and a wind speed of 40 hz to prepare a flame retardant foam having a folding rate of 10 times, min.

[ Comparative Example  2-1]

1. Mixture preparation process

32.0 kg of LDPE (L), 7.0 kg of azodicarbonamide (100% conversion standard), 1.0 kg of zinc stearate (Zn-st) and 60.0 kg of magnesium hydroxide are mixed to prepare a base plate mixture.

2. Extrusion process

-The base plate prepared in 1. above was fed into a twin-screw extruder (screw rotational speed, 20 rpm) preheated at a temperature of cylinder and dice of 140 ° C at a feed rate of 120 kg / hr to prepare a sheet having a length × width × thickness of 200 m × 670 mm × A base plate having a thickness of 0.5 mm is extrusion-molded.

3. Electron Beam Bridging Process

-The base plate extruded in 2. above is charged and pulled at a speed of 30 m / min to an electron beam crosslinking apparatus having a voltage of 500 kV and an electron dose of 2Mard to prepare a base plate having a crosslinking degree of 50%.

4. Foaming Process

- A flask subjected to cross-linking treatment in step 4 was charged at a rate of 9 m / min using a foam furnace preheated to a temperature of 250 DEG C and a wind speed of 40 hz to prepare a flame retardant foam having a folding rate of 10 times, min.

[ Comparative Example  2-2]

1. Mixture preparation process

72.0 kg of LDPE (L), 7.0 kg of azodicarbonamide (100% conversion standard), 1.0 kg of zinc stearate (Zn-st) and 20.0 kg of raw material are mixed to prepare a base plate mixture.

2. Extrusion process

-The base plate prepared in 1. above was fed into a twin-screw extruder (screw rotational speed, 20 rpm) preheated at a temperature of cylinder and dice of 140 ° C at a feed rate of 120 kg / hr to prepare a sheet having a length × width × thickness of 200 m × 670 mm × A base plate having a thickness of 0.5 mm is extrusion-molded.

3. Electron Beam Bridging Process

-The base plate extruded in 2. above is charged and pulled at a speed of 30 m / min to an electron beam crosslinking apparatus having a voltage of 500 kV and an electron dose of 2Mard to prepare a base plate having a crosslinking degree of 50%.

4. Foaming Process

- A flask subjected to cross-linking treatment in step 4 was charged at a rate of 9 m / min using a foam furnace preheated to a temperature of 250 DEG C and a wind speed of 40 hz to prepare a flame retardant foam having a folding rate of 10 times, min.

[ Comparative Example  2-3]

1. Mixture preparation process

- A base plate mixture was prepared by mixing 82.0 kg of LDPE (L), 7 kg of azodicarbonamide (100% conversion standard), 1.0 kg of zinc stearate (Zn-st), 7.5 kg of DBDPO and 2.5 kg of Sb ₂ O ₃ .

2. Extrusion process

-The base plate prepared in 1. above was fed into a twin-screw extruder (screw rotational speed, 20 rpm) preheated at a temperature of cylinder and dice of 140 ° C at a feed rate of 120 kg / hr to prepare a sheet having a length × width × thickness of 200 m × 670 mm × A base plate having a thickness of 0.5 mm is extrusion-molded.

3. Electron Beam Bridging Process

-The base plate extruded in 2. above is charged and pulled at a speed of 30 m / min to an electron beam crosslinking apparatus having a voltage of 500 kV and an electron dose of 2Mard to prepare a base plate having a crosslinking degree of 50%.

4. Foaming Process

- A flask subjected to cross-linking treatment in step 4 was charged at a rate of 9 m / min using a foam furnace preheated to a temperature of 250 DEG C and a wind speed of 40 hz to prepare a flame retardant foam having a folding rate of 10 times, min.

[Test]

Five specimens were obtained from the flame-retardant foam prepared by the method of Test Example 2 and Comparative Examples 2-1 to 2-3, respectively. Then, according to the test method by UL94HF-1, And the ignition of the indicator cotton were tested and the results shown in Table 2 below were obtained.

[result]

As shown in Table 2, the flame-retarded foam prepared according to Test Example 2 of the present invention had good process stability even during the extrusion process and the foaming process, and had a relatively high density compared with Comparative Examples 2-1 and 2-2 , It can be seen that the cushion feeling is more excellent and it is found that both the flushing time, the residual time, the carbonization up to the mark of 60 mm and the ignition of the indicator cotton are all suitable, and the degree of detection of the halogen substance .

On the contrary, in Comparative Example 2-1 (only the inorganic metal-based flame retardant is used as the flame retardant) and Comparative Example 2-2 (only the phosphorus flame retardant is used as the flame retardant), the process stability in the extrusion process and the foaming process is poor , The density is higher than that of Test Example 2, the feeling of cushioning is less and the degree of detection of the halogen substance (regulated substance) is also satisfactory, but the flame retardancy indicating that the flame retardant time, the remaining time, the carbonization to the 60 mm marking line, Able to know.

The foamed foam according to Comparative Example 2-3, in which a halogen-based flame retardant and an inorganic flame retardant (antimony trioxide) are used as flame retardants, has a good process stability in the extrusion process and the foaming process, has a density similar to that of Test Example 2, However, there is a problem that a large amount of bromine, which is a regulated substance, is detected.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It is possible to carry out various changes in the present invention.

S100: Mixture preparing step S200: Extrusion step
S300: crosslinking and foaming step S300 ': electron beam crosslinking step
S300 ": foaming process

Claims (12)

Based on 100 parts by weight of a base resin composed of an ethylene-vinyl acetate (EVA) copolymer resin or a polyolefin-based copolymer resin,
A base flake mixture comprising 2 to 40 parts by weight of a blowing agent, 0.1 to 5 parts by weight of a crosslinking agent, and 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic flame retardant agent and a phosphorus flame retardant agent is extruded, chemically crosslinked, Wherein the foam is foamed as a foam to form a foam.
The method according to claim 1,
Wherein the matrix mixture comprises
With respect to 100 parts by weight of the base resin,
And 0.1 to 5 parts by weight of a coupling agent.
The method according to claim 1,
The composite flame retardant of the matrix blend,
50 to 80% by weight of an inorganic metal-based flame retardant and 20 to 50% by weight of a phosphorus-based flame retardant.
The method of claim 3,
The inorganic metal-
Halogen-free flame-retarded foamed foam comprising at least one of aluminum hydroxide, aluminum trioxide, antimony trioxide, antimony pentoxide, magnesium hydroxide, zinc stannate, molybdic acid or zirconium.
The method of claim 3,
The phosphorus-
A halogen-free flame-retardant foamed foam comprising at least one of ammonium phosphate, ammonium polyphosphate, metal phosphinate, and melamine polyphosphate.
Based on 100 parts by weight of a base resin composed of an ethylene-vinyl acetate (EVA) copolymer resin or a polyolefin-based copolymer resin,
(S100) preparing a base plate mixture comprising 2 to 40 parts by weight of a blowing agent, 0.1 to 5 parts by weight of a crosslinking agent, and 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant;
An extrusion step (S200) of extruding the base plate prepared in the mixture preparing step (S100) into a base plate having a certain width and thickness using an extruder having a cylinder and a die temperature of 90 to 210 DEG C;
A crosslinking / foaming step (S300) of chemically crosslinking the base plate extruded by the extrusion step (S200) as a crosslinking agent included in the mixing preparation step (S100) in a foaming furnace at 140 to 300 DEG C, and decomposing and foaming the foaming agent; Wherein the halogen-free flame-retardant foam is formed by a method comprising the steps of:
Based on 100 parts by weight of a base resin composed of an ethylene-vinyl acetate (EVA) copolymer resin or a polyolefin-based copolymer resin,
A base plate mixture comprising 2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a foaming aid, and 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant is extruded into a base plate, Is crosslinked and is configured to be foamed as a foam furnace to be made into a foam.
8. The method of claim 7,
Wherein the matrix mixture comprises
With respect to 100 parts by weight of the base resin,
And 0.1 to 5 parts by weight of a coupling agent.
8. The method of claim 7,
The composite flame retardant of the matrix blend,
50 to 80% by weight of an inorganic metal-based flame retardant and 20 to 50% by weight of a phosphorus-based flame retardant.
10. The method of claim 9,
The inorganic metal-
Halogen-free flame-retarded foamed foam comprising at least one of aluminum hydroxide, aluminum trioxide, antimony trioxide, antimony pentoxide, magnesium hydroxide, zinc stannate, molybdic acid or zirconium.
11. The method of claim 10,
The phosphorus-
A halogen-free flame-retardant foamed foam comprising at least one of ammonium phosphate, ammonium polyphosphate, metal phosphinate, and melamine polyphosphate.
Based on 100 parts by weight of a base resin composed of an ethylene-vinyl acetate (EVA) copolymer resin or a polyolefin-based copolymer resin,
2 to 40 parts by weight of a foaming agent, 0.1 to 5 parts by weight of a foaming aid, and 15 to 85 parts by weight of a composite flame retardant mixed with an inorganic metal flame retardant and a phosphorus flame retardant;
An extrusion step (S200) of extruding the base plate prepared in the mixture preparing step (S100) into a base plate having a certain width and thickness using an extruder having a cylinder and a die temperature of 90 to 210 DEG C;
An electron beam cross-linking step (S300 ') of irradiating a base plate extruded by the extrusion step (S200) with an electron beam having a voltage of 100 to 1500 kv and an electron dose of 0.1 to 5.0 Mrad to bridge the base plate;
And a foaming step (S300 ") of foaming the base plate subjected to the electron beam cross-linking step (S300 ') at a temperature of 140 to 300 DEG C as a foaming furnace.

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