KR102405947B1 - A epoxy composition for forming and molded product using thereof - Google Patents

Abstract

The epoxy composition according to the present invention has excellent weather resistance while satisfying mechanical properties enhanced by including a curing agent, a foaming agent and a filler of a specific composition in the epoxy resin.
As the foam molded foam according to the present invention has the above characteristics, it can be used for general adhesives, sealing materials, cushioning materials, etc., especially for interiors that maintain or increase the strength of the metallic structure when manufacturing automobiles and other transportation means It can be used as a cushioning material. In addition, it may be used for manufacturing a laminate for reinforcement and reinforcement of a frame, a roof, a wall, and the like of a building.

Description

Epoxy composition for foaming and foaming molded article including same {A epoxy composition for forming and molded product using thereof}

The present invention relates to an epoxy composition for foaming and a foamed molded article comprising the same, and more particularly, by including a curing agent, a foaming agent and a filler in an epoxy resin, while satisfying enhanced mechanical properties, the cell structure of the foam can be maintained in a compact form It relates to an epoxy composition and an expanded molded article.

It is known that many industries, such as the automotive industry, require parts with both strength and lightness. In an effort to strike a balance between this strength and minimum weight, hollow parts are used that are dried from relatively thin sheets of metal. However, hollow metal parts are easily deformed. Accordingly, it is also known that the presence of structural foams within the cavities of hollow parts can improve the strength and stiffness of such parts. For flat parts of automobile bodies such as doors, roofs, trunk lids or bonnets, it is known to increase the rigidity and rigidity of the parts by bonding a sheet based on foamed or non-foaming epoxy or polyurethane resins to the parts. have.

The specific preparation of foam structures varies widely. For example, US Pat. No. 5,575,526 teaches structural foams based on various resins comprising Preparation 2, which includes 54.5% EPON 828 epoxy resin, 7.5% HALOXY 62 epoxy diluent, 6.1% DER 732 Flexible Epoxy, 2.0% EXPANCEL 551DU Blowing Agent, 8.8% MICROS Microspheres, 17.7% 3M K20 Microspheres and 3.4% DI-CY dicyandiamide curing agent. U.S. Pat. No. 5,755,486 discloses materials based on thermally expandable resins, which materials are, for example, epoxy resins, acrylonitrile-butadiene rubber, calcium carbonate, carbon black, fumigated silica, glass spheres. , curing agents, accelerators and foaming agents.

In the case of such an epoxy foam structure, several problems are scattered, but the biggest problem is to have a relatively short shelf life. Ideally, the ingredients of such a formulation should remain stable once associated with each other, should not react under normal conditions during storage and loading, and when stored at room temperature or above for weeks or months, the formulation It is desirable that the characteristics of

Another problem of the epoxy foam structure is that it does not satisfy basic mechanical properties, particularly strength. This is due to the characteristics of the epoxy resin, and the compatibility with fillers or other polymer resins mixed together, especially with non-polar polymer resins, is poor, and changes such as shrinkage due to stress during curing occur adversely affecting mechanical properties. .

US Patent Publication No. 5,575,526 (May 18, 1994) US Patent Publication No. 5,755,486 (May 22, 1995)

The present invention has been devised to solve the above problems, and in particular, it relates to an epoxy composition and an expanded molded article having excellent weather resistance while satisfying enhanced mechanical properties by including a curing agent, a foaming agent and a filler of a specific composition in an epoxy resin. .

The present invention relates to an epoxy composition for foaming and a foamed molded article comprising the same.

An aspect of the present invention mainly comprises 80 to 90% by weight of a polyfunctional epoxy resin, 3 to 10% by weight of a foaming agent, 1 to 10% by weight of a surfactant, and 1 to 10% by weight of a filler, and an amine-based curing agent 10 to 10% by weight as a curing agent It relates to an epoxy composition for foaming, characterized in that it contains 50 to 90% by weight of a polyamide-type curing agent in 50% by weight.

In the present invention, the polyfunctional epoxy resin has one or more epoxy groups in the main chain, a hydroxyl group, an alkoxy key, a halogen group, an aldehyde group, a carbonyl group, a carboxyl group, an amine group, a nitrile group, a nitro group, an amide group and an imide group. Or it includes a plurality of functional groups, and the foaming agent is characterized in that it includes any one or a plurality selected from organosilane, organosilazane, polymethylsiloxane, organohydrogenpolysiloxane, and organosiloxane oligomer.

In addition, the surfactant is dodecyl polyoxyethylene ether, tridecyl polyoxyethylene ether, alkyl polyglycoside, alkyl phenol ethoxylate, benzyl alcohol, n-butyl glycidyl ether, polyoxyethylene alkyl ether, polyoxyethylene Sulfosuccinic acid ester salt of alkyl ether, sulfate ester salt of polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, sulfosuccinic acid ester salt of polyoxyethylene phenyl ether, sulfate ester salt of polyoxyethylene phenyl ether, polyoxyethylene alkylphenyl Ether, sulfosuccinic acid ester salt of polyoxyethylene alkylphenyl ether, sulfate ester salt of polyoxyethylene alkylphenyl ether, polyoxyethylene aralkylphenyl ether, sulfosuccinic acid ester salt of polyoxyethylene aralkylphenyl ether, polyoxyethylene ar Sulfate ester salts of alkylphenyl ether, phosphate ester salts of polyoxyethylene alkylphenyl ether, aliphatic or aromatic carboxylate salts of polyoxyethylene alkylphenyl ether, acidic phosphoric acid (meth)acrylic acid ester emulsifier and rosin glycidyl ester acrylic It is characterized in that it contains any one or a plurality selected from acid anhydride-modified products of the rate.

In addition, the filler is any one selected from calcium carbonate, calcium oxide, talc, coal tar, carbon black, glass fiber, carbon fiber, silicate, mica, powdered quartz, aluminum oxide, bentonite, wollastonite, kaolin, fumed silica and silica airgel Including one or more, the amine-based curing agent is 1,3-benzenedimethanamine, ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexa Methylenediamine, trimethylhexamethylenediamine, diethylenetriamine, iminobispropylamine, bis(hexamethylene)triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra (hydroxyethyl)ethylenediamine, triethyleneglycoldiamine, tetraethyleneglycoldiamine, diethyleneglycolbis(propylamine), polyoxypropylenediamine, polyoxypropylenetriamine, isophoronediamine, metacenediamine, N-aminoethyl Piperazine, bis(4-amino-3-methyldicyclohexyl)methane, bis(aminomethyl)cyclohexane, 3,9-bis(3-aminopropyl)2,4,8,10-tetraoxaspiro (5 ,5) undecane, norbornenediamine, tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4 -diaminoanisole, 2,4-toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino1,2-diphenylethane, 2 ,4-diaminodiphenylsulfone, m-aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethyl)phenol, triethanolamine, methylbenzylamine, α-(m-aminophenyl)ethylamine; α-(p-aminophenyl)ethylamine, diaminodiethyldimethyldiphenylmethane, and α,α'-bis(4-aminophenyl)-p-diisopropylbenzene characterized.

In addition, the polyamide-based curing agent includes any one or a plurality selected from polyamidoamine, diethylene triamine, triethylenetetraamine, tetraethylene pentaamine, 3,3-amino bispropylamine and m-xylenediamine characterized in that

In addition, the epoxy composition for foaming is characterized in that 20 to 50 parts by weight of a curing agent is mixed with respect to 100 parts by weight of the main material, and the epoxy composition for foaming is a diluent, thermoplastic polymer powder, coupling agent, plasticizer, rheology agent, wetting agent, adhesive, stability It is characterized in that it further comprises any one or a plurality of additives selected from the agent and the colorant.

Another aspect of the present invention relates to a foamed molded article comprising the epoxy composition for foaming.

The epoxy composition according to the present invention has excellent weather resistance while satisfying mechanical properties enhanced by including a curing agent, a foaming agent and a filler of a specific composition in the epoxy resin.

As the foam molded foam according to the present invention has the above characteristics, it can be used for general adhesives, sealing materials, cushioning materials, etc., especially for interiors that maintain or increase the strength of the metallic structure when manufacturing automobiles and other transportation means It can be used as a cushioning material. In addition, it may be used for manufacturing a laminate for reinforcement and reinforcement of a frame, a roof, a wall, and the like of a building.

Hereinafter, the epoxy composition for foaming according to the present invention and a foamed molded article including the same will be described in more detail through specific examples or examples. However, the following specific examples or examples are only a reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Also, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of effectively describing particular embodiments only and is not intended to limit the invention.

Throughout this specification, unless the context requires otherwise, the terms "comprises" and "comprising" include, but are not limited to, a given step or element, or group of steps or elements, but any other step or element, or It is to be understood that a step or group of elements is not excluded.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

The epoxy composition for foaming according to the present invention is composed of a two-component type, and is mainly based on a multifunctional epoxy resin, and may include a foaming agent, a surfactant, and a filler. In addition, the curing agent for curing the epoxy resin may include an amine-based curing agent and a polyamide curing agent.

In the present invention, the epoxy resin is a thermosetting resin having one or a plurality of epoxy groups, and by including one or more functional groups as well as an epoxy group, it induces chemical bonding with other compositions to increase the compatibility of the composition and the mechanical properties of the foam. do.

The epoxy resin is also called a polyepoxide, and in principle, it may be a saturated, unsaturated, cyclic or acyclic aliphatic, cycloaliphatic, aromatic or heterocyclic polyepoxide. Examples of polyepoxides may include polyglycidyl ethers produced by reaction of epichlorohydrin or epibromohydrin or polyphenols in the presence of an alkali.

Examples of the polyphenol include resorcinol, pyrocatechol, hydroquinone, bisphenol A (bis(4-hydroxy-phenyl)-2,2-propane), bisphenol F (bis(4-hydroxyphenyl)methane ), bis(4-hydroxyphenyl)-1,1-isobutane, 4,4'-dihydroxybenzophenone, bis(4-hydroxyphenyl)-1,1-ethane and 1,5-hydroxy and hydroxynaphthalene, and among these, those based on bisphenol A or bisphenol F polyphenols are preferable because the heat resistance, impact resistance and moisture resistance of the foam can be improved.

Another polyepoxide is a polycarboxylic acid or polyglycidyl ester of a hydroxycarboxylic acid, for example glycidol or epichlorohydrin with an aliphatic or aromatic polycarboxylic acid such as oxalic acid, succinic acid, glue from the reaction products of tarric acid, phthalic acid, tetrahydrophthalic acid, terephthalic acid, dimer fatty acids or p-hydroxybenzoic acid or beta-hydroxy naphthoic acid, or from the epoxidation products of olefinically unsaturated cycloaliphatic compounds, or from natural oils and fats or Derived from synthetic polyolefins. Other suitable polyepoxides include glycidylated aminoalcohol compounds and aminophenol compounds, hydantoin diepoxides and urethane-modified epoxy resins.

The epoxy resin as described above may include one or a plurality of functional groups. As described above, the epoxy resin having a functional group may reduce the viscosity of the composition and impart amorphous properties, and may act as a reactive diluent by increasing compatibility with other non-polar compositions or polar compositions.

The polyfunctional epoxy resin may have one or more, more preferably two or more functional groups in one unit structure constituting the repeating unit. At this time, examples of the functional group include a hydroxyl group, an alkoxy key, a halogen group, an aldehyde group, a carbonyl group, a carboxyl group, an amine group, a nitrile group, a nitro group, an amide group, an imide group, etc. These may be included alone or two or more.

In the present invention, the polyfunctional epoxy resin is not limited in viscosity or epoxy equivalent. For example, the polyfunctional epoxy resin may have a viscosity of 10 to 20,000 cPa at 25° C., more preferably 100 to 15,000 cPa, in terms of workability and miscibility. In addition, the epoxy equivalent may be 100 to 700 g / eq, more preferably 150 to 350 g / eq can maintain the heat resistance, impact resistance, moisture resistance, etc. of the coating film is preferable.

In addition, the foam composition may further include one or a plurality of epoxy resins to supplement heat resistance, impact resistance, flexibility, etc. in addition to the polyfunctional epoxy resin. At this time, the added epoxy resin is not limited in the present invention, but may include a bisphenol-based epoxy resin and a modified epoxy resin.

For example, the bisphenol-based epoxy resin may have a structure of Formula 1 below.

[Formula 1]

(In Formula 1, R ₁ and R ₂ may each independently be hydrogen or a (C1-C10) alkyl group, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a ethyl group, an isopentyl group , a neopentyl group, or a tert-pentyl group.)

The bisphenol-based epoxy resin may be a liquid bisphenol-based epoxy resin in order to increase compatibility with the composition. In particular, since it is necessary to increase the compatibility with other compositions and to prevent pinholes in the composition to increase mechanical strength, a low viscosity, specifically, 1,000 to 20,000 cPa at 25°C is preferable.

The modified epoxy resin is intended to significantly increase the flexibility, which is a disadvantage of the epoxy resin, to increase mechanical properties. In particular, when modified with an aliphatic amine-based compound, free rotational motion due to molecular chains between crosslinking points is improved, thereby increasing flexibility.

In this case, the aliphatic amine compound is preferably a carboxyl terminated butadiene acrylonitrile (CTBN) copolymer, a phenol terminated butadiene acrylonitrile (PTBN) copolymer, an epoxy terminated butadiene acrylonitrile (ETBN) copolymer, a hydroxyl terminated butadiene acrylonitrile (HTBN) copolymer, etc. There, these modified epoxy resins can serve as plasticizers in the composition to impart physical properties such as flexibility and water resistance.

The polyfunctional epoxy resin is preferably included in an amount of 80 to 90% by weight of 100% by weight of the total main material. When added less than the above range, the mechanical properties of the composition may decrease, and if it exceeds the above range, the flexibility of the composition may decrease and miscibility with other compositions may occur.

In the present invention, the foaming agent is a silicone compound containing silicon hydride, and exhibits high reactivity with the functional group contained in the above-described polyfunctional epoxy resin, and in particular, hydrogen or combustible gas is generated by a hydroxyl group, etc., so that the composition can be foamed. have.

Examples of the blowing agent as described above include organosilane, organosilazane, polymethylsiloxane, organohydrogenpolysiloxane, and organosiloxane oligomer, and specifically, trimethylchlorosilane, dimethylchlorosilane, and methyltrichlorosilane. organochlorosilanes such as; organic trialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, ethyltrimethoxysilane, and n-propyltrimethoxysilane; diorganodialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, and diphenyldimethoxysilane; triorganoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane; partial condensates of these organoalkoxysilanes; organosilazanes such as hexamethyldisilazane; polymethylsiloxane, organohydrogenpolysiloxane, organosiloxane oligomer having a silanol group or an alkoxy group; and the like.

More preferably, polymethylsiloxane is mentioned as the blowing agent. The polymethylsiloxane is a polymer containing methyl groups and hydrogen along the siloxane chain, and is usually used as various coatings and treatment agents such as softeners and waterproofing agents, but reacts with alcohol, aldehyde, ketone, olefin, acid, acid catalyst, base, etc. to form hydrogen and The same gas can be generated.

In addition, when an acid or base catalyst (eg, Lewis acid, base, clay, etc.) is present in the polymethylsiloxane, highly flammable by-products such as Me3SiH, Me ₂ SiH ₂ , MeSiH ₃ are produced according to the characteristics of the main siloxane chain even in the absence of moisture. The redistribution of the formed siloxane chain occurs, and through this, a flammable gas such as silane gas (SiH ₄ ) is generated to cause foaming of the composition.

In the present invention, the foaming agent preferably comprises 3 to 10% by weight of 100% by weight of the total main composition. When the foaming agent is added below the above range, foaming of the composition may be insufficient, and when added above the above range, an uncontrolled exothermic reaction may occur, which may cause deterioration of the epoxy resin.

In the present invention, the surfactant is used to impart properties such as lowering of surface tension, wetting, emulsification, solubilization, dispersibility, and foaming properties of the composition. plays a role

In the present invention, it is preferable to use a reactive surfactant among various surfactants as the surfactant. Since the reactive surfactant as described above contains a functional group capable of reacting during curing of the composition, it also acts as a monomer during the curing process and reduces the amount of the surfactant remaining after polymerization, so it can be prepared into a foam having improved mechanical properties. .

The reactive surfactant as described above is mainly an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, a propyl group, and a pentyl group, an aryl group having 6 to 20 carbon atoms such as a phenyl group, a naphthyl group, an anthryl group, an aralkyl group, an arylene group It may contain a hydrophobic group, such as an alkoxy group, a hydroxyl group, and a hydrophilic group, such as an epoxy group. Examples of such reactive surfactants include silicone-based surfactants, polyethylene glycol, polypropylene glycol, dodecyl polyoxyethylene ether, tridecyl polyoxyethylene ether, alkyl polyglycoside, alkylphenol ethoxylate, benzyl alcohol, n- butylglycidyl ether, polyoxyethylene alkyl ether, sulfosuccinic acid ester salt of polyoxyethylene alkyl ether, sulfate ester salt of polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, sulfosuccinic acid ester salt of polyoxyethylene phenyl ether; Sulphate ester salt of polyoxyethylene phenyl ether, polyoxyethylene alkylphenyl ether, sulfosuccinic ester salt of polyoxyethylene alkylphenyl ether, sulfate ester salt of polyoxyethylene alkylphenyl ether, polyoxyethylene aralkylphenyl ether, polyoxy Sulphosuccinic acid ester salts of ethylene aralkylphenyl ether, sulfate ester salts of polyoxyethylene aralkylphenyl ether, phosphate ester salts of polyoxyethylene alkylphenyl ether, aliphatic or aromatic carboxylate salts of polyoxyethylene alkylphenyl ether, acid and phosphoric acid (meth)acrylic acid ester emulsifiers and acid anhydride-modified products of rosin glycidyl ester acrylate.

Among them, it is most preferable to use alkylglycidyl ether, alkylphenol ethoxylate, benzyl alcohol, polyethylene glycol, polypropylene glycol, and silicone-based surfactants from the viewpoint of emulsification.

In the present invention, the surfactant is preferably included in an amount of 1 to 10% by weight of 100% by weight of the total main composition. When the surfactant is added below the above range, the fluidity of the composition is lowered and mixing is not performed properly. When the surfactant is added in excess of 10% by weight, a rapid curing reaction occurs at the same time as the composition is mixed due to excessive reactivity, and the moldability is greatly deteriorated. can

In the present invention, the filler improves the mechanical properties and heat resistance of the foam, and serves to promote the foaming action through reaction with the above-described foaming agent.

Examples of such fillers include calcium carbonate, calcium oxide, talc, coal tar, carbon black, glass fiber, carbon fiber, silicate, mica, powdered quartz, aluminum oxide, bentonite, wollastonite, kaolin, fumed silica and silica airgel. and the like, and these may be used alone or in combination of two or more.

More preferably, fumed silica is used as the filler. The fumed silica is a structure in which a large number of hydroxyl groups are arranged on the surface of silicon, and improves low brittleness, which is the biggest disadvantage of an epoxy resin, and when uniformly dispersed, thermal properties such as thermal stability and thermal conductivity of the composition, breaking strength and tensile strength, etc. While improving the mechanical properties, the silanol group on the surface reacts with the foaming agent to promote the generation of foaming gas.

The filler may include various inorganic or organic particles used as a thixotropic agent or a rheology modifier in addition to the above components. For example, organic or inorganic fibers such as wollastonite fibers, carbon fibers, ceramic fibers, and aramid fibers, hollow beads based on phenolic resin, epoxy resin or polyester, (meth)acrylic acid ester copolymer, polystyrene, styrene/ (meth)acrylate copolymers and in particular polymeric microparticles such as polyvinylidene chloride and copolymers of vinylidene chloride with acrylonitrile or (meth)acrylic acid esters, fly ash or cashew nuts, cork, coke and the like may be further included.

Among them, the filler may further increase mechanical properties and increase the foaming effect by further adding fibers based on aramid fibers, carbon fibers, aluminum fibers, glass fibers, polyamide fibers, polyethylene fibers or polyester fibers.

The filler preferably includes 1 to 10% by weight of 100% by weight of the main material. When less than 1% by weight is added, the above-described properties, in particular, the foaming effect of the foaming agent may be insufficient, and when added in excess of the above range, phase separation of the composition may occur and mechanical properties may be rather deteriorated.

In the present invention, the main material is not limited to the manufacturing method. For example, first, a foaming agent is mixed with a polyfunctional epoxy resin, and then the mixture is stirred at a speed of 300 to 700 rpm under a temperature of 70 to 80° C. using a homogenizer or an impeller. Then, a surfactant is added thereto and stirred at the same speed using residual heat. After the filler is added to the composition in which the surfactant is added as described above and sufficiently stirred, an additional epoxy may be further mixed thereto as needed to complete the casting.

The main material according to the present invention may further add additives of various components in addition to the above components. In this case, the additive may be any one or a plurality selected from a diluent, a thermoplastic polymer powder, a coupling agent, a plasticizer, a rheology agent, a wetting agent, an adhesive, a stabilizer, and a colorant, and in addition to these, a foaming accelerator, a coupling agent, etc. may be further included. free

For example, the foaming accelerator may further include urea, organic acids, oxides such as platinum, amines, lead, tin, zinc, calcium, cadmium, and salts thereof, but the present invention is not limited thereto.

In addition, the coupling agent includes silanes and organometalates, such as organic silanes, titanates, zirconates, and the like, as long as commercially available coupling agents are not limited thereto.

In the present invention, the curing agent is for curing the epoxy of the main material, it can be cured at room temperature, and it is a two-component composition in which the main material and the curing agent are separately measured and mixed, but chemical resistance, heat resistance, impact resistance, and moisture resistance Due to its excellent properties, it can be used for various purposes such as composite materials for aviation, ships, automobiles, etc., insulation materials, mold materials, adhesives, etc. desired in the present invention.

More preferably, the curing agent in the present invention may be a mixture of an amine-based curing agent and a polyamide-type curing agent. The curing agent as described above may react with a polyfunctional epoxy resin, in particular, a bisphenol-based epoxy resin to greatly increase mechanical strength.

In the present invention, the amine-based curing agent serves to improve the chemical resistance, water resistance and heat resistance of the composition by increasing the crosslinking density of the composition. may include

For example, the amine-based curing agent as described above, 1,3-benzenedimethanamine, ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylene Diamine, trimethylhexamethylenediamine, diethylenetriamine, iminobispropylamine, bis(hexamethylene)triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra( Hydroxyethyl)ethylenediamine, triethyleneglycoldiamine, tetraethyleneglycoldiamine, diethyleneglycolbis(propylamine), polyoxypropylenediamine, polyoxypropylenetriamine, isophoronediamine, metacenediamine, N-aminoethyl pipette Razine, bis(4-amino-3-methyldicyclohexyl)methane, bis(aminomethyl)cyclohexane, 3,9-bis(3-aminopropyl)2,4,8,10-tetraoxaspiro (5, 5) Undecane, norbornenediamine, tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4- Diaminoanisole, 2,4-toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino1,2-diphenylethane, 2, 4-diaminodiphenylsulfone, m-aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethyl)phenol, triethanolamine, methylbenzylamine, α-(m-aminophenyl)ethylamine, α -(p-aminophenyl)ethylamine, diaminodiethyldimethyldiphenylmethane, and α,α'-bis(4-aminophenyl)-p-diisopropylbenzene, among which 1,3-benzenedi The use of methanamine increases the curing rate at room temperature, and can impart a higher glass transition temperature, improved chemical resistance, and mechanical properties of the composition.

The polyamide-based curing agent is directly polymerized with the epoxy resin to give a plurality of functional groups to the epoxy resin. In particular, the amide group hydrogen bonds with the functional groups such as the above-described filler, particularly fumed silica, to improve the heat resistance and durability of the composition. serves to further enhance it.

The polyamide-based curing agent may be an aliphatic polyamide or an aromatic polyamide, and the type thereof may be freely changed according to the purpose of use of the foam. For example, when the foam requires flexibility, it is preferable to use an aliphatic polyamide rather than an aromatic polyamide. In order to further improve heat resistance or mechanical properties, it is preferable to use an aromatic polyamide.

For example, the polyamide-based curing agent in the present invention, any one selected from polyamidoamine, diethylene triamine, triethylenetetraamine, tetraethylene pentaamine, 3,3-amino bispropylamine and m-xylenediamine One or more may be mentioned, and among them, polyamidoamine is preferably used because flexibility is satisfied and heat resistance can also be controlled by freely controlling the molecular chain length of polyamidoamine.

In addition, the curing agent may further include an auxiliary curing agent in addition to the amine-based and polyamide-type curing agents. Examples of the auxiliary curing agent include imidazole, p-chlorophenyl-N,N-dimethylurea (MONURON), 3-phenyl-1,1-dimethylurea (FENURON) or 3,4-dichlorophenyl-N,N- substituted ureas such as dimethylurea (DIURON), amino compounds such as tertiary aryl- or alkylamines such as benzyldimethylamine, tris(dimethylamino)phenol, piperidine or piperidine derivatives, amine salts and A quaternary ammonium compound etc. are mentioned.

In the present invention, it is preferable that 50 to 90% by weight of the polyamide-type curing agent is added to 10 to 50% by weight of the amine-based curing agent. If it is out of the above range, the mechanical properties of the composition may be deteriorated or the miscibility between the respective compositions may be deteriorated.

In addition, the curing agent may further include one or more ionomers to improve mechanical properties by increasing chemical bonding between the compositions in addition to the amine-based and polyamide-based compositions.

The ionomer means that a part of the carboxylic acid group of the copolymer of ethylene acrylic acid or ethylene methacrylic acid is substituted with a metal cation. As the preferred ionomer used in the present invention, an olefin copolymer such as ethylene and zinc Contains carboxylic acid neutralized with metal ions such as (Zn), sodium (Na), magnesium (Mg) or lithium (Li), and contains unsaturated carboxylic acids such as acrylic or methacryl acid. A copolymer may be used.

Commercially used ionomers include SURLYN 8140 as a grade neutralized by sodium, and SURLYN 9910 as a grade neutralized by zinc, but are not limited thereto.

The ionomer is preferably added in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the total curing agent. When added below the above range, the effect of improving various properties due to the addition of the ionomer does not appear, and when added above the above range, the curing rate rapidly increases due to excessive increase in interfacial miscibility, and the moldability and mechanical properties of the composition may decrease. have.

As described above, the foam molded foam according to the present invention is prepared in the form of a composition by first mixing the components constituting the main material, and then mixing the polyamide-based curing agent and the amine-based curing agent, and mixing other additives thereto. desirable. In this case, it is preferable to mix the composition at a temperature of 100° C. or less, more preferably at room temperature (around 20° C.), particularly while adding the curing agent.

In addition, the composition ratio of the main material and the curing agent is not limited in the present invention, but it is preferable to mix 20 to 50 parts by weight of the curing agent relative to 100 parts by weight of the main material because moldability and foaming properties can be satisfied.

The mixed composition as described above may be stored in the middle or may be directly transferred to equipment for further processing such as an injection molding machine, an extruder or a calendering machine. In particular, in order to manufacture an expanded molded foam, it is preferable to put the composition in an injection mold, foam and harden it, and also maintain the temperature of the mold at room temperature.

The foam molded foam prepared as described above can be used for various purposes. Specifically, there are general adhesives, sealing materials, cushioning materials, and the like, and in particular, it can be used as a cushioning material for interiors that maintains or increases the strength of the metallic structure when manufacturing automobiles and other means of transportation. In addition, it may be used for manufacturing a laminate for reinforcement and reinforcement of a frame, a roof, a wall, and the like of a building.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. However, the following examples are only for explaining the present invention in detail, and the scope of the present invention is not limited by these examples.

The specifications and methods of measuring physical properties of the specimens prepared through the following Examples and Comparative Examples are as follows.

(composition)

The specifications of the compositions used through Examples and Comparative Examples are shown in Table 1 below.

[Table 1]

(mechanical properties)

ⓐ Tensile strength and elongation: Conducted in accordance with ASTM D 638.

ⓑ Flexural strength and flexural modulus: Conducted in accordance with ASTM D 790.

ⓒ IZOD Impact strength: Conducted according to ASTM D 256.

(Examples 1 to 3, Comparative Examples 1 to 4 and 6 to 11)

A composition was prepared based on the composition ratio of Table 2 below, but the mixing temperature of the composition was room temperature (20° C.), and the stirring speed was 500 rpm. The prepared composition was first pre-gelled for 5 minutes, cured and foamed for 30 minutes in an injection device to complete a specimen having a size of 10 cm × 10 cm × 1 cm. The physical properties of the finished specimens were measured and shown in Table 3 below.

[Table 2]

(In Table 2, the ionomer means the amount added (parts by weight) based on 100 parts by weight of the total curing agent.)

[Table 3]

As shown in Table 3, it can be seen that the expanded molded foam manufactured according to the present invention exhibits high values in all mechanical properties such as tensile strength, elongation, flexural strength, flexural modulus, and impact strength. In particular, in the case of Example 2 in which the ionomer was further added, it can be seen that all mechanical properties were improved compared to Example 1 in which the ionomer was not added. It seems that the impact strength has increased due to chemical bonding with other epoxy resins or fillers.

As described above, although the electromagnetic wave shielding sheet according to the present invention has been described in detail above, this is merely an example and it is common in the art that various changes and modifications are possible within the scope without departing from the technical spirit of the present invention. Engineers will be able to understand it well.

Claims (10)

Mainly comprising 80 to 90% by weight of a polyfunctional epoxy resin, 3 to 10% by weight of a foaming agent, 1 to 10% by weight of a surfactant, and 1 to 10% by weight of a filler,
Curing agent 1,3-benzenedimethanamine, ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, diethylene Triamine, iminobispropylamine, bis(hexamethylene)triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra(hydroxyethyl)ethylenediamine, triethylene Glycoldiamine, tetraethyleneglycoldiamine, diethyleneglycolbis(propylamine), polyoxypropylenediamine, polyoxypropylenetriamine, isophoronediamine, metacenediamine, N-aminoethylpiperazine, bis(4-amino-3) -Methyldicyclohexyl)methane, bis(aminomethyl)cyclohexane, 3,9-bis(3-aminopropyl)2,4,8,10-tetraoxaspiro(5,5)undecane, norbornenediamine , tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4-diaminoanisole, 2,4- Toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino1,2-diphenylethane, 2,4-diaminodiphenylsulfone, m -Aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethyl)phenol, triethanolamine, methylbenzylamine, α-(m-aminophenyl)ethylamine, α-(p-aminophenyl)ethylamine , diaminodiethyldimethyldiphenylmethane and α,α'-bis(4-aminophenyl)-p-diisopropylbenzene in 10 to 50 wt% of any one or a plurality of amine-based curing agents selected from polyamidoamine 50 to 90% by weight,
The composition is an epoxy composition for foaming, characterized in that it further comprises 0.1 to 1 part by weight of the ionomer relative to 100 parts by weight of the curing agent.
The method of claim 1,
The polyfunctional epoxy resin has one or a plurality of epoxy groups in the main chain, hydroxyl group, alkoxy key, halogen group, aldehyde group, carbonyl group, carboxyl group, amine group, nitrile group, nitro group, any one or a plurality of selected from amide group and imide group Epoxy composition for foaming, characterized in that it contains a functional group.
The method of claim 1,
The foaming agent is an epoxy composition for foaming, comprising any one or a plurality selected from organosilane, organosilazane, polymethylsiloxane, organohydrogenpolysiloxane and organosiloxane oligomer.
The method of claim 1,
The surfactant is dodecyl polyoxyethylene ether, tridecyl polyoxyethylene ether, alkyl polyglycoside, alkyl phenol ethoxylate, benzyl alcohol, n-butyl glycidyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl Sulfosuccinic acid ester salt of ether, sulfate ester salt of polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, sulfosuccinic acid ester salt of polyoxyethylene phenyl ether, sulfate ester salt of polyoxyethylene phenyl ether, polyoxyethylene alkylphenyl ether , sulfosuccinic acid ester salt of polyoxyethylene alkylphenyl ether, sulfate ester salt of polyoxyethylene alkylphenyl ether, polyoxyethylene aralkylphenyl ether, sulfosuccinic acid ester salt of polyoxyethylene aralkylphenyl ether, polyoxyethylene aralkyl Sulfuric ester salt of phenyl ether, phosphate ester salt of polyoxyethylene alkylphenyl ether, aliphatic or aromatic carboxylate salt of polyoxyethylene alkylphenyl ether, acidic phosphoric acid (meth)acrylic acid ester emulsifier and rosin glycidyl ester acrylate Epoxy composition for foaming, characterized in that it comprises any one or a plurality selected from the acid anhydride-modified of.
The method of claim 1,
The filler is any one selected from calcium carbonate, calcium oxide, talc, coal tar, carbon black, glass fiber, carbon fiber, silicate, mica, powdered quartz, aluminum oxide, bentonite, wollastonite, kaolin, fumed silica and silica airgel Or an epoxy composition for foaming, characterized in that it comprises a plurality.
delete delete The method of claim 1,
The epoxy composition for foaming is an epoxy composition for foaming, characterized in that it is mixed in an amount of 20 to 50 parts by weight of a curing agent based on 100 parts by weight of the main material.
The method of claim 1,
The epoxy composition for foaming further comprises any one or a plurality of additives selected from a diluent, a thermoplastic polymer powder, a coupling agent, a plasticizer, a rheology agent, a wetting agent, an adhesive, a stabilizer, and a pigment.
A foamed molded article comprising the epoxy composition for foaming according to any one of claims 1 to 5, 8 and 9.