KR20030013831A - Metal compound resin composition and a sheet for intercepting electromagnetic waves and a method for fabricating the same - Google Patents

Abstract

PURPOSE: Provided are a metal composite resin composition for screening electromagnetic waves, which is excellent in heat-resistance, weather-resistance, flexibility, and stretching ability, and an electromagnetic wave-screening sheet and a process for producing the composition and the sheet. CONSTITUTION: The metal composite resin composition comprises 100pts.wt. of a polymer resin, 300-1000pts.wt. of metal alloy(like sandust) flakes, 60-150pts.wt. of saturated fatty acid- or oleic acid-coated aluminum hydroxide or magnesium hydroxide as a non-halogen inorganic fire-retardant agent, 0.5-5pts.wt. of red phosphorus, and 0.3-5pts.wt. of sulfur, a sulfur donor, a peroxide crosslinking agent, wherein the polymer resin comprises 20-80wt% of a polyolefin resin, 20-100wt% of a copolymer of a carboxyl-contained monomer or a derivative thereof and ethylene, and 5-80wt% of a polyolefin resin graft-modified by unsaturated carboxylic acid or a derivative thereof. And the electromagnetic wave-screening sheet comprises the metal composite resin composition and is produced by orienting and laminating the polymer resin composition and the metal alloy flakes in the same direction as the sheet.

Description

Metal compound resin composition and a sheet for intercepting electromagnetic waves and a method for fabricating the same

The present invention relates to an electromagnetic shielding sheet and a method for maintaining the electromagnetic shielding properties through a strong graft bond between the metal composite resin composition and the conductive polymer and the polymer resin for the purpose of electromagnetic shielding.

The recent development of scientific civilization has provided many conveniences to human life. In particular, the development of electrical, electronic and communication-related equipment is playing a part in making our lives more convenient and profitable. The scientific civilization, which provides convenience to humans, has both sides which may be good or bad depending on how and where it is used.

One of the latest scientific literature that harms humans is electromagnetic waves. From power generation and transmission, radio and television and telephone communications, microwave ovens, ovens, and space exploration on airplanes and ships, everything is unimaginable. As technology develops, electronics will pour and electromagnetic waves will increase. Even now, electromagnetic waves wander around us as colorless and odorless, like the air we breathe. However, these electromagnetic waves, which are indispensable to humans, are also called electromagnetic interference (EMI), which disturbs other electromagnetic waves, causing malfunction of various machines, causing industrial accidents, and directly or indirectly affecting the human body. In addition, for example, the efficiency and lifespan of internal electronic products may be reduced due to the high voltage generator of the automobile, the disturbance between electronic equipments, glaucoma, which may occur in the case of long-term exposure to microwaves, and the reproductive ability may be reduced. The space inhabited by modern people is no longer a safe zone from electromagnetic waves, and as scientific civilization develops, its seriousness will increase. The human body has a microscopic electronic signaling system that enables mechanisms of emotion regulation, memory, and behavior. Pregnancy, childbirth, illness and stress in human history would be shocking if they were never related to electromagnetic waves, but that is true. Under these circumstances, advanced countries such as the United States, Japan, and Russia have established safety exposure standards for electromagnetic waves to strongly regulate external exposure, and continue to study the harmfulness of electromagnetic waves.

In particular, the advanced countries have already been around 20 years ago in order to keep up with high-quality information and minimize the effects on human body, which is derived in proportion to the rapidly increasing information and communication in the 21st century. EMI has been regulated and in recent years, it has been very active in protecting the electromagnetic environment by forcing electromagnetic wave immunity.

In general, when a metal is used as a base material of a conventional EMI material, a polymer material is mainly used as a binder concept. A rubber system such as a silicone copolymer or a terpolymer of chlorinated polyethylene, chloro sulfonated polyethylene, ethylene propylene diene, and ethylene propylene copolymer Although it is used as a non-crosslinking type or a crosslinking type, the EMI material has a metal content of more than 70wt%, so that the composite which is simply mechanically mixed or blended (particularly in the case of thermoplastic) has almost no physical property ( Elongation 100% ~ 0%) The heat resistance is also very poor. In the case of the crosslinking type, the heat resistance is improved, but since the metal and the polymer are basically in a state of mechanically mixing, there is a problem in that the physical properties of the material are not good, so that the basic physical properties of shielding the electromagnetic waves cannot be continuously maintained, but are cured or decomposed.

In the case of metal resin composites made of resins containing halogens, such as chlorinated polyethylene, in the case of combustion, they produce dioxin and furan, which are harmful to humans and peripherals and must be exported to the Americas or Europe. I am struggling with regulation. Although it is not a fire, halogen-based resins are continuously desorbed by aging and curing of polymers. This phenomenon is very serious in non-crosslinked composites, and these resin composites can be used as EMI materials. In this case, there is a risk of continually causing corrosion in peripheral devices and electronic devices, and it is difficult to continuously maintain the inherent characteristics of shielding electromagnetic waves.

The object of the present invention is to mechanically and physically as well as chemically combine the conductive polymer and the polymer resin to solve the above problems to realize excellent physical properties and heat resistance and to maximize the excellent electromagnetic shielding properties by adding a non-halogen flame retardant inorganic material Method for manufacturing electromagnetic shielding sheet with high efficiency by orienting and laminating the electromagnetic shielding metal composite resin composition and conductive polymer resin composition and metal alloy flake in the same direction as the sheet It is about.

1 is an electromagnetic wave shielding efficiency (a) of an electromagnetic wave shielding sheet made of a blend of a sender and a polymer resin composition of a metal alloy prepared according to the present invention, and an electromagnetic wave of a brand two-layer lamination of sender and a polymer resin composition of a metal alloy. It is a graph which shows the electromagnetic wave shielding efficiency (b) of a shielding sheet.

Figure 2 is a graph showing the electromagnetic wave shielding efficiency (a) of the electromagnetic wave shielding sheet made of the polyaniline salt and the polymer resin composition prepared by the present invention and the electromagnetic wave shielding efficiency (b) of the electromagnetic wave shielding sheet made of the polypyrrole and the polymer resin composition.

The present invention relates to an electromagnetic wave shielding sheet according to a blend of a conductive polymer and a polymer resin composition for the purpose of electromagnetic wave shielding, and a polymer metal composite resin composition thereof, wherein the polyolefin resin and preferably a polar resin are ethylene and an acrylic acid copolymer or Unsaturated carboxylic acid and its derivatives are used alone or in blends with radically polymerized polyolefin resins to maximize the compatibility of conductive polymers and resin compositions through strong chemical bonds (grafts) between conductive polymers and polymer resins. The present invention provides an electromagnetic shielding sheet, and a method of manufacturing the multilayered resin composition, which are oriented and laminated through a blend of a conductive resin and a conductive polymer capable of continuously maintaining excellent electromagnetic shielding properties.

The composition of the present invention for achieving the above object is a polyolefin resin or a copolymer of a monomer having a carboxyl group or a derivative thereof and a copolymer of ethylene, unsaturated carboxylic acid or a derivative thereof polyolefin resins alone or To provide a metal composite resin composition obtained by adding aluminum hydroxide, magnesium hydroxide or flame retardant as a metal, metal alloy flake and inorganic flame retardant to a blended polymer resin, and an electromagnetic wave shielding composite resin sheet composed of the composite resin composition. It is done.

The composition may contain an antioxidant, a sunscreen agent, a processing aid, a crosslinking agent, a crosslinking aid and the like in addition to the above components.

The ethylene copolymer used in the present invention is a copolymer of ethylene and a monomer having a carboxyl group or a derivative thereof, preferably ethylene ethyl acrylate, ethylene methyl acrylate or ethylene vinyl acetate.

Specific examples of graft modification by reactive monomer include a method of grafting unsaturated carboxylic acid to improve adhesion and compatibility or providing reactivity, and a method of preparing reactive polyolefin by grafting an organosilane compound. It is a so-called post-reactor modification method for grafting various kinds of reactive monomers to a special function (adhesiveness, reactivity, polarity) while maintaining the properties of the polyolefin resin as a base resin.

The mechanism for improving the adhesion between the metal or the metal alloy flake and the resin may be explained by the diffusion of the polar group present in the functional polyolefin as well as the factor due to the chemical bonding as described above. That is, when the functional polyolefin (polar polymer) and the metal flake are brought into contact with each other in a molten state, the mobility of the polar group (eg, acrylic acid group, maleic anhydride group, etc.) in the functional polyolefin increases with time, and thermodynamically the polar polymer and the metal flake It moves to the interface. This lowers the interfacial energy between the metal and the polar polymer, thereby forming a strong bonding force at the interface. This reaction can be achieved by measuring the concentration of the polar group at the interface when the functional polyolefin is bonded to the substrate. The functional polyolefin alone is present at the interface after contact with other substrates compared to the amount of polar groups present on the surface. It can be confirmed from the fact that the amount of polar groups is higher. The deciding factor of the strength of adhesion is the total content of the polar groups present in the functional polyolefin, and the other important process variables are temperature and time during compounding and sheeting. The higher the processing temperature, the lower the viscosity of the functional polyolefin, which increases the mobility of the polar group, making it easier to move to the interface, which can lead to an effect of improving the bond strength between the resin and the metal. By increasing the content of the polar group to move can also improve the bonding strength of the resin and the metal.

When filling a large amount of metal flakes (an inorganic flame retardant may be added) to the polar polyolefin resin, the resin in the form of pellets is first processed into kneaders, banbury mixers or rolls first in sheet form. Add the metal flakes and other additives and compound them in a kneader, Benbury mixer, booth kneader or open roll mill, or mix pellet resin and metal flakes and other additives first in a Henschel mixer, ribbon blender, V blender, etc. There is a method of compounding in a Benbury mixer, booth kneader, single extruder, twin extruder, etc. The compound may be a continuous ribbon or pellet form.

The method of laminating the compound into sheets typically includes a calender method and a T-die extrusion method. In the present invention, in order to orient and laminate the metal flakes in a direction parallel to the sheet, two or more rolls may be rolled after calendering as well as a calender. It is characterized by calendaring. The calender should be at least three rolls of 12-20 inches and preferably at least four rolls. In order to obtain a laminate sheet of constant thickness, the calender work temperature and the placement of the chill roll are important.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

According to the present invention, 100 parts by weight of a functional polar polyolefin resin is first processed into a sheet form in a kneader, a banbury mixer or a roll, and 300 to 1000 parts by weight of a planar sender, which is a metal alloy flake, is mixed. 60 to 150 parts by weight of aluminum hydroxide (or magnesium hydroxide) as inorganic and flame retardant

Add 0.5 to 5 parts by weight to compound in a kneader, Benbury mixer, booth kneader or open roll mill, or mix the mixture first in a Henschel mixer, ribbon blender, V blender, etc., then kneader, Benbury mixer, sub-kneader, single extruder There is a method of compounding in a twin extruder, etc. The compound may be a continuous ribbon or pellet form. The method of laminating the compound into a sheet is to provide a sheet for shielding electromagnetic waves having flexibility and elongation by calendering with four bone rolls after the extrusion as well as the calender in order to orient and laminate the metal flakes in a direction parallel to the sheet. Could be manufactured.

The method for producing the functional polar polyolefin resin used above is as follows.

Polyolefin resin 20 to 80% by weight of monomers or derivatives thereof having carboxyl groups and copolymers of ethylene 20 to 100% by weight unsaturated carboxylic acid or derivatives thereof It is resin which is single or blended and mixed by 100 weight part of resin.

Ethylene copolymers used in the present invention are copolymers of ethylene and a monomer having a carboxyl group or a derivative thereof. For example, ethylene vinyl acetate (EVA), ethylene ethyl acrylate (EEA), ethylene methyl acrylate (EMA) ), Ethylene butyl acrylate (EBA), ethylene methyl methacrylate (EMMA), ethylene acrylic acid (EAA) or ethylene methacrylic acid copolymer (EMAA) and the like can be used alone or in combination, preferably ethylene ethyl acrylate , Ethylene methyl acrylate or ethylene vinyl acetate.

The content of the carboxyl group of the ethylene copolymer is preferably in the range of 5 to 50% by weight. When the content of the carboxyl group is less than 5% by weight, the flexibility of the polyolefin resin and the metal alloy flakes is poor, and Difficult to fill, the mechanical strength is lowered, when the content of the carboxyl group exceeds 50% by weight has a disadvantage of poor compatibility with other polyolefin resins, the appearance and physical properties of the sheet is deteriorated and the adhesiveness is increased, worse the workability of the calendar.

A specific method of graft modification by reactive monomer is a so-called post-reactive modification to graf various kinds of reactive monomers to the polyolefin backbone.

As a modification method, special functions (adhesiveness, reactivity, polarity) were given while maintaining the properties of the polyolefin resin as the base resin.

The graft-modified polyolefin resin used in the present invention is reacted and extruded by adding 0.5 to 4% by weight of an unsaturated carboxylic acid or a derivative thereof to the polyolefin resin in the presence of an organic peroxide, and the grafted composition or the graft composition and the polyolefin resin It is a mixture with. The polyolefin resin may be a copolymer of ethylene and α-olefin, low density polyethylene, linear low density polyethylene, ultra low density polyethylene, vinyl acetate or a copolymer of ethylene and octene-1, and the like. Acrylic acid, methacrylic acid, maleic acid, fumaric acid, citraconic acid, or anhydrides thereof may be used as the derivative, and maleic anhydride is particularly preferable. In the present invention, the effect of grafting the metal and metal alloy flakes to the polymer resin is obtained by strongly chemically bonding the -OH group attached to the anhydride of the unsaturated carboxylic acid and the metal and metal alloy flakes.

Example 2

In the same manner as in the sheet manufacturing method of Example 1, one or more selected from the group selected from the group consisting of ferrite, nickel, zinc, and manganese mixed in a functional polar polyolefin resin prepared in Example 1 with at least one of two or more. Metals include silver, iron, and iron-nickel mixtures [model name; 120 HF (55.58 to 44.42, 54.25 to 45.75 weight ratio), HF120 (54.29 to 45.71 weight ratio), 120 MMP (20.70 to 79.93 weight ratio), MMP120 (29.88 to 70.12 weight ratio)],

Iron-silicon mixture [Model name: 80FS120 (92.37 to 7.63 weight ratio), 120FS (93.29 to 6.71weight

B)], aluminum-iron-silicon mixture [Model name: 200SDST325 (6.59 vs 81.34 vs 12.06 weight)

B), from 300 to 1000 parts by weight of one species selected from the group selected from the group selected from 325SDST (6.99 to 81.77 to 11.24 weight ratio), and the aluminum hydroxide (or magnesium hydroxide) at 60

150 parts by weight, 0.5 to 5 parts by weight of a flame retardant aid is compounded in a kneader, a Benbury mixer, a booth kneader or an open roll mill, or mixed in a Henschel mixer, ribbon blender, V blender, etc. There is a method of compounding in a burr mixer, busne kneader, single extruder, twin extruder, etc. The compound may be a continuous ribbon or pellet form. The method of laminating the compound to the sheet is to provide a electromagnetic shielding sheet having flexibility and stretchability by calendering with four bone rolls after the T die extrusion as well as a calender in order to orient and laminate the metal flakes in a direction parallel to the sheet. Could be manufactured.

Example 3

In a functional polar polyolefin resin prepared in the same manner as in Example 1, a polyaniline salt, which is a conductive polymer, was mixed at 300 to 1000 parts by weight, and aluminum hydroxide (or magnesium hydroxide) 60 to 150 parts by weight as an inorganic flame retardant, and a flame retardant aid. Of

0.5 to 5 parts by weight of compounding in a kneader, Benbury mixer, booth kneader or open roll mill or mixing the mixture first in a Henschel mixer, ribbon blender, V blender, etc., and then kneader, Benbury mixer, booth kneader, single extruder There is a method of compounding in a twin extruder, etc. The compound may be a continuous ribbon or pellet form. The method of laminating the compound to a sheet is a sheet for shielding electromagnetic waves having flexibility and stretchability by calendering with four bone rolls after T die extrusion as well as a calender in order to orient and laminate a metal flake in a direction parallel to the sheet. Could be manufactured.

Method for producing a polyaniline salt of the conductive polymer used in the above is as follows.

Aniline (C ₆ H ₅ NH ₂ , 99.55, purchased by Aldrich Co.) was purified using a general vacuum distillation apparatus and stored in a refrigerator in a brown bottle. Ammonium peroxide [(NH ₄ ) S ₂ O ₈ )] to be used as an oxidant was purchased (Aldrich Co.) and used as it is.

First, 500 ml of 1 mol hydrochloric acid solution was prepared. 20 mL of aniline was dissolved in 300 mL of 1 mol hydrochloric acid solution and kept at 0 ° C. (0 ° C. to 60 °). Separately, 11.5 g of [(NH ₄ ) S ₂ O ₈ )] was dissolved in 200 ml of 1 mol hydrochloric acid solution and maintained at 0 ° C. (0 ° C. to 60 ° C.). The solution containing the oxidant was slowly added to the solution containing the aniline over 2 minutes using a separatory funnel.

After 90 minutes, the precipitate was filtered using a Whatman filter paper (# 1) in a Buchner funnel connected to an aspirator, and the precipitate was washed with each used positive asset. The filtered piece (sample) was made into a turbid solution in 10 ml of 1 mole hydrochloric acid, and then stirred in a 500 ml 1 mole hydrochloric acid solution and stirred with a magnetic paddle. After 15 hours, the aspirator was removed using Whatman filter paper (# 2). Filtration in a Buchner funnel connected with. At this time, 2L of 1 mol hydrochloric acid was used to wash the filtrate until it was completely colorless. The obtained sample was vacuum dried for 24 hours or more. This gave a polyaniline salt doped with a positive asset.

Example 4

In the same manner as in the sheet manufacturing method of Example 3, the conductive polar polyolefin resin was mixed with 300 parts by weight of polypyrrole, which is a conductive polymer, to prepare an electromagnetic shielding sheet having flexibility and stretchability.

Method for producing a polypyrrole of the conductive polymer used in the above is as follows.

Pyrrole (manufactured by Aldrich Co., USA) was purified using a general vacuum distillation apparatus and stored in a refrigerator in a brown bottle. Naphthalenesulfonic acid, iron chloride (FeCl ₃ ) to be used as an oxidant was purchased (Aldrich Co.) and used as a dopant.

At 0 ° C, 0.4 mol pyrrole and 0.4 mol naphthalenesulfonic acid are added to 900 ml distilled water in a 1 L beaker and stirred with a magnetic stirrer. Separately, 1.2 mol iron chloride (FeCl ₃ ) is added to 100 ml distilled water in a 500 ml beaker and stirred with a magnetic stirrer. At 0 ° C. 0.15 mol ammonium persulfate solution is slowly added to the pyrrole and naphthalenesulfonic acid mixture. Stir the reaction slowly with a magnetic stir for 4 hours.

After the reaction was completed, the reaction solution was washed with distilled water and methanol in a Buchner funnel, filtered, and the obtained pieces were placed in a drying tube connected to a vacuum line for 24 hours. ^-3 torr).

As mentioned above, the large amount of conductive polymer is chemically combined with the polymer resin to significantly improve the physical properties and weather resistance, and maximize the shielding characteristics by orientation lamination of metal flakes or conductive polymers. It is not only excellent in environmental, economical and mechanical properties, but also uniformly distributed and excellent in electromagnetic wave shielding efficiency. By processing the electromagnetic shielding sheet having the flexibility and stretchability can be used as an electromagnetic shielding material for electronic, semiconductor, information and communication devices, mobile phones and mobile device case (case).

Claims (7)

(1) 20 to 80% by weight polyolefin resin (2) 20 to 100% by weight copolymer of monomer or derivative thereof having carboxyl group and ethylene (3) Polyolefin graft-modified with unsaturated carboxylic acid or derivatives thereof 5 to 80 wt% resin Metal alloy with respect to 100 weight part of polymer resins which are a mixture of the said component (1), (2), (3) 300 to 1000 parts by weight of flakes, 60 to 150 parts by weight of aluminum hydroxide or magnesium hydroxide coated with saturated fatty acid or oleic acid with a non-halogen inorganic flame retardant, and 0.5 to 5 parts by weight of sulfur in the case of the crosslinking type. Electromagnetic shielding metal composite resin composition or metal composite resin sheet comprising a sulfur donor, 0.3 to 5 parts by weight of peroxide crosslinking agent The method of claim 1, wherein the polyolefin resin is ultra-low density polyethylene resin, linear low density polyethylene resin, low density polyethylene resin, medium density polyethylene resin, high density polyethylene resin, chlorinated polyethylene, chlorosulfonated polyethylene having a melt index of 0.5 to 30 g / 10 minutes Electromagnetic shielding metal composite resin composition or metal composite resin sheet, characterized in that one or more selected from the group consisting of a copolymer resin of ethylene and propylene The method of claim 1, wherein the copolymer having a carboxyl group or a derivative thereof and ethylene is ethylene vinyl acetate, ethylene ethyl acrylate, ethylene methyl acrylate, ethylene butyl acrylate, ethylene methyl methacrylate, ethylene acrylic acid , Ethylene methacrylic acid copolymer and rubber based one or more selected from the group consisting of acrylic elastomers, metal composite resin composition or metal composite resin sheet for shielding The metal composite resin composition or metal composite resin sheet for electromagnetic wave shielding according to claim 1, wherein the unsaturated carboxylic acid or derivative thereof is acrylic acid, methacrylic acid, maleic acid, fumaric acid, citraconic acid or anhydride thereof. The electromagnetic wave shield according to claim 1, wherein the polyolefin resin of (1) or (3) is a copolymer of ethylene and α-olefin, a copolymer of ethylene and octene-1 using an ethylene vinyl acetate or metallocene catalyst. Metal composite resin composition or metal composite resin sheet In the processing of the metal composite resin composition for shielding electromagnetic waves of thermoplastic resin according to claim 1, a three-roll, preferably four-roll or more calender is oriented by laminating a metal alloy flake in a direction parallel to the sheet and laminating to a thickness of 0.05 to 3 mm to form a roll. After winding with or by primary setting with a T-die extruder, orientating and laminating the metal flakes in a direction parallel to the sheet with a roll of two rolls, preferably three rolls or more, and laminating to a thickness of 0.05 to 3 mm to roll them into rolls. Method for producing a metal composite resin composition or sheet for electromagnetic shielding The method according to claim 1, wherein the resin is prepared by adding 1 to 300 parts by weight of a polyaniline salt, polypyrrole, and the like selected from conductive polymers based on 100 weights of the resin.