KR100730984B1 - Adhesive composition for flexible copper clad laminated film - Google Patents

Abstract

Provided is an adhesive composition for the copper clad laminate(CCL) of a flexible printed circuit board which is excellent in flexibility, heat resistance, adhesive strength, and insulating property. The adhesive composition comprises 100 parts by weight of an acrylic copolymer resin which comprises 1-20 wt% of an acrylic copolymer having a weight average molecular weight of 500-500,000 and 80-99 wt% of an acrylic copolymer having a weight average molecular weight of 1,500,000-3,500,000; 5-50 parts by weight of an epoxy resin having at least two epoxy groups; 0.05-5 parts by weight of a curing agent; 5-50 parts by weight of a flame retardant compound; and 1-30 parts by weight of an inorganic filler, wherein the flame retardant compound is at least one selected from a fluorine-based compound, a chlorine-based compound, a bromine-based compound and an iodine-based compound.

Description

Adhesive composition for flexible copper clad laminated film {ADHESIVE COMPOSITION FOR FLEXIBLE COPPER CLAD LAMINATED FILM}

The present invention relates to an adhesive composition for a flexible copper-clad laminate, and more particularly, to an adhesive composition for a flexible copper-clad laminate having excellent flexibility, excellent heat resistance and adhesiveness, and thus excellent adhesive strength, long-term heat resistance, soldering heat resistance, The present invention relates to an adhesive composition for flexible copper foil laminated films capable of producing a flexible copper foil laminated film for a flexible printed circuit board having excellent properties such as chemical resistance, flexibility, and insulation.

Recently, the trend of miniaturization, high integration, simplification, high performance, etc. has been prominent in the electric and electronic industries. In order to satisfy such demands, it is absolutely necessary to develop flexible printed circuit boards having good flexibility and integration of circuits. The flexible printed circuit board is flexible and can be folded according to the internal structure of the product. Since the flexible printed circuit board is made of a very thin material, the flexible printed circuit board occupies little space and has the advantage of sufficiently serving as a circuit board.

In general, a flexible printed circuit board is a copper base or aluminum attached to a film such as a polyimide resin, a polyester resin, a polyamideimide resin, a polyesterimide resin, and the like as a basic substrate. Since these films are used as substrates, they have excellent thermal, mechanical, and electrical properties, so that an adhesive is applied to these substrates, and a conductor such as copper or aluminum is adhered to, and screen printing and dry film photoresistors on the metal conductor surface are used. The circuit is printed using and the metal foil is etched. In order to protect the printed circuit, coverlay film is coated with an adhesive on a film of the same material as the original and semi-cured, and then a film or paper having a release property is used as a protective sheet on the adhesive surface, and when used, peel off the release film or the release paper. It is protected by covering the printed circuit surface on the flexible printed circuit board.

The adhesive used in the manufacture of the flexible printed circuit board and the coverlay film is excellent in heat resistance, chemical resistance, solvent resistance, electrical insulation, flame retardancy, water resistance and flexibility. The flow out should be small and the gaps between the circuits should be well-filled and the life span of the semi-cured state should be long. The shelf life should be approximately three months at room temperature and six months at 5 ° C.

Adhesives used in flexible printed circuit boards include acrylonitrile-butadiene rubber / epoxy resins (Japanese Patent Application No. 10-79079, Japanese Patent Application No. 3-186787), Polyester / Epoxy Watches (Japanese Patent Application No. 63-297438, Japanese Patent Application) Sodium 63-275178, Japanese Laid-Open Patent No. 1-170091), Butyral resin series, Nylon / Epoxy resin series (Japanese Laid-Open Patent No. 7-64997), Acrylic resin / phenolic resin series (Japanese Laid-Open Patent Publication No. 61-261307), Acrylic resin series (EP 0201102, Japanese Patent Application Laid-Open No. 57-59973).

An object of the present invention was devised to provide a new adhesive composition for a flexible copper clad laminated film that satisfies all the above-described characteristics, such as excellent adhesion, long-term heat resistance, soldering heat resistance, chemical resistance, flexibility, insulation properties, etc. It is an object of the present invention to provide an adhesive composition for a flexible copper foil laminated film that can produce an excellent flexible copper foil laminated film for a flexible printed circuit board.

These and other objects and advantages of the present invention will become more apparent from the following description of preferred embodiments.

Adhesive composition for a flexible copper clad laminated film according to the present invention for achieving the above object is an adhesive composition for a flexible copper foil laminated film laminated with an insulating film, an adhesive and a copper foil, the adhesive composition (a) weight average molecular weight 500 ~ 500,000 100 parts by weight of an acrylic copolymer resin consisting of 1 to 20% by weight of an acrylic copolymer and 80 to 99% by weight of an acrylic copolymer having a weight average molecular weight of 1,500,000 to 3,500,000, and (b) 5 to 50 weight of an epoxy resin having two or more epoxy groups. (C) 0.05 to 5 parts by weight of the curing agent, (d) 5 to 50 parts by weight of the flame retardant compound, and (e) 1 to 30 parts by weight of the inorganic filler.

Preferably, the acrylic copolymer resin is acrylonitrile, alkyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, n-octyl arclate, acrylic acid, methacrylic acid, itaconic acid, 4- Prepared using at least one of hydroxybutyl acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate or 2-hydroxypropylene glycol (meth) acrylate It is done.

More preferably the acrylic copolymer resin is 10 to 50 parts by weight of acrylonitrile, 40 to 80 parts by weight of alkyl acrylate having an alkyl group having 2 to 12 carbon atoms, 1 to 10 parts by weight of acrylic acid or methacrylic acid and hydroxyethyl It is characterized by consisting of 1 to 5 parts by weight of acrylate or hydroxy ethyl methacrylate.

Also preferably, the epoxy resin is at least one of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol noblock type epoxy resin, a cresol noblock type epoxy resin, or a rubber modified epoxy resin.

Also preferably, the curing agent is at least one of an amine curing agent, a guanidine curing agent, an imidazole curing agent, a phenol curing agent, or an acid anhydride curing agent.

Also preferably, the flame retardant compound is at least one of a fluorine compound, a chlorine compound, a bromine compound or an iodine compound.

Also preferably, the inorganic filler is characterized in that at least one of aluminum oxide, magnesium oxide, silicon oxide, titanium oxide, antinium oxide, zinc oxide or molybdenum oxide.

Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention. These examples are only presented by way of example only to more specifically describe the present invention, it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited by these examples. .

In the composition of the adhesive composition for flexible copper-clad laminate according to the present invention, the functional group-containing acrylic copolymer having a weight average molecular weight of 500 to 500,000 based on 100 parts by weight of the acrylic copolymer resin is 1 to 20% by weight and the weight average molecular weight is 1,500,000 to 3,500,000. It is preferable that it is reactive acrylic copolymer resin which consists of 80-99 weight% of functional group containing acrylic copolymers. If the acrylic copolymer having a weight average molecular weight of 500 to 500,000 in less than 1% by weight in 100 parts by weight of the acrylic copolymer resin, the flexibility is lowered. If it exceeds 20% by weight, the flexibility is increased, but the heat resistance is lowered, and the weight average molecular weight is 1,500,000. If the acrylic copolymer of 3,500,000 is less than 80% by weight, the heat resistance is lowered. If the acrylic copolymer is more than 99% by weight, the heat resistance and adhesiveness are improved, but the flexibility is deteriorated.

Epoxy resin in the adhesive composition for a flexible copper clad laminate according to the present invention is preferably at least one of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol noble type epoxy resin, a cresol noble type epoxy resin or a rubber modified epoxy resin. On the basis of 100 parts by weight of the acrylic copolymer resin, the content is preferably 5 to 50 parts by weight. It is because if it is less than 5 weight part, heat resistance and adhesiveness will fall, and if it exceeds 50 weight part, flexibility will fall and it will break easily.

The low molecular weight acrylic copolymer resin has a weight average molecular weight in the range of 500 to 500,000, and the ultra high molecular weight acrylic copolymer resin has a weight average molecular weight in the range of 1,500,000 to 3,500,000, which is used for polymerization The monomer composition is based on 100 parts by weight of the acrylic copolymer resin 10 to 50 parts by weight of acrylonitrile, 40 to 80 parts by weight of alkyl acrylate having an alkyl group having 2 to 12 carbon atoms, 1 to 10 parts by weight of acrylic acid or methacrylic acid and The hydroxyethyl acrylate or the hydroxy ethyl methacrylate is preferably composed of 1 to 5 parts by weight.

The acrylonitrile makes the adhesive have a strong resistance to organic chemicals such as acetone, methylene chloride, toluene used in the process of flexible printed circuit board, the alkyl acrylate having a lower alkyl group gives the flexibility of the resin In addition, the acrylic acid or methacrylic acid has a carboxyl group, thereby improving the adhesiveness of the adhesive and serves to adjust the crosslinking density. In addition, the hydroxyethyl acrylate or hydroxy ethyl methacrylate gives excellent adhesion.

The alkyl acrylate having an alkyl group having 2 to 12 carbon atoms is ethyl acrylate, propyl acrylate, n-butyl acrylate, iso-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, iso-octyl Acrylate, lauryl acrylate, stearyl acrylate, cyclohexyl acrylate, benzyl acrylate and the like, but is not limited thereto. The alkyl acrylates may be used alone or in combination of two or more thereof.

The functional group-containing monomer having the above reactivity includes a vinyl monomer containing a carboxyl group, a vinyl monomer containing a hydroxy group, a vinyl monomer containing an amino group, a vinyl monomer containing an epoxy group, and a vinyl group containing an acetoacetyl group. A monomer etc. are mentioned. Among these, the monomer containing a carboxyl group and the monomer containing a hydroxy group are the most preferable. Vinyl monomers having a carboxyl group include, but are not limited to, acrylic acid, beta-carboxyethyl acrylate, itaconic acid, crodonic acid, maleic acid, maleic anhydride, and butyl maleic acid. In addition, the vinyl monomer having a hydroxy group is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, chloro-2-hydroxypropyl ( Meta) acrylate, diethylene glycol mono (meth) acrylate, aryl alcohol and the like. The amino group-containing monomers include aminomethyl (meth) acrylate, dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate and vinylpyridine. Furthermore, the monomer containing an epoxy group, such as glycidyl (meth) acrylate, and the monomer containing an acetoacetyl group, such as acetoacetoxyethyl (meth) acrylate, etc. are mentioned. The said functional group containing monomer can be used individually or in combination of 2 or more types.

The functional group of the multifunctional compound reacts with the functional group having the reactivity of the acrylic copolymer, and may be at least two functional groups, preferably 2 to 4 functional groups in one molecule. Examples of the curing agent for such a multifunctional compound include an epoxy curing agent, an amine curing agent, a metal chelate curing agent, an aziridine curing agent, and the like.

The said epoxy hardening | curing agent is bisphenol A, an epoxy resin of epichlorohydrin type, ethylene glycol glycidyl ether, polyethyleneglycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6- Hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diglycidylamine, N, N, N ', N'-tetraglycidyl-m-xylenediamine and 1, 3-bis (N, N'- diglycidyl amine methyl) cyclohexane etc. are mentioned.

Examples of the amine curing agent include hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethyltetramine, isoformdiamine, amino resins and methylene resins.

Examples of the metal chelate compound include compounds in which polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium are coordinated with acetylacetone or ethyl acetoacetate. .

The aziridine-based curing agent is N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxide), N, N'-toluene-2,4-bis (1-aziridinecarboxes Id), triethylenemelamine, bisisophthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphineoxide, N, N'-hexamethylene-1,6-bis (1-aziri Dicarboxylic acid), trimethylolpropane-tri-beta-aziridinylpropionate, tetramethylolmethane-tri-beta-aziridinylpropionate, and the like.

The multifunctional curing agent may be used in an amount of usually 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the high molecular weight acrylic copolymer. By using a polyfunctional hardening | curing agent in such content, a preferable three-dimensional crosslinked structure is formed between the said high molecular weight (meth) acrylic-type copolymer. In addition, these polyfunctional hardeners can be used individually or in combination.

Any known method may be employed for producing the low molecular weight acrylic copolymer and the ultrahigh molecular weight acrylic copolymer constituting the acrylic copolymer resin of the adhesive composition for flexible copper foil laminated film according to the present invention.

The ultra high molecular weight acrylic copolymer is. 0.01 to 0.5 parts by weight of a polymerization initiator (azo-based polymerization initiators such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, peroxides such as benzoyl peroxide and acetyl peroxide, diphenyl ketone, 2- Photopolymerization initiators such as hydroxy-2-methyl-1-phenyl-propan-1-one and the like), and are synthesized by a method such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, and preferably solution polymerization. Are synthesized. In the case of the solution polymerization method, ethyl acetate, toluene, hexane, acetone, and the like are used as the polymerization solution, and the reaction temperature is 50 to 150 ° C, preferably 50 to 110 ° C, and the reaction time is 2 to 15 hours, preferably 7 To 10 hours.

The low-molecular weight acrylic copolymer is synthesized by a method such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, and the like, preferably ultra-high molecular weight acrylic copolymer. 0.01 to 0.1 parts by weight of a polymerization initiator (azo-based polymerization initiators such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, peroxides such as benzoyl peroxide and acetyl peroxide, diphenyl ketone, 2- Photopolymerization initiators such as hydroxy-2-methyl-1-phenyl-propan-1-one and the like), and are synthesized by a method such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, and preferably solution polymerization. Are synthesized. In the case of the solution polymerization method, ethyl acetate, toluene, hexane, acetone and the like are used as the polymerization solution, and the reaction temperature is 50 to 150 ° C, preferably 50 to 110 ° C, and the reaction time is 2 to 15 hours, preferably 5 To 10 hours.

On the other hand, the acrylic copolymer resin for flexible copper-clad laminate according to the present invention includes a low molecular weight acrylic copolymer, an ultra high molecular weight acrylic copolymer and a crosslinking agent as described above, and also include a weather stabilizer, a tachyfire, a plasticizer, Softeners, dyes, pigments, silane coupling agents, inorganic fillers and the like can be further blended.

The epoxy compound of the adhesive composition for flexible copper-clad laminate according to the present invention reinforces the adhesive strength of the adhesive and reacts with the carboxyl group and the curing agent of the acrylic copolymer to form a net structure and impart rigidity and heat resistance to the adhesive. In particular, the epoxy compound may use at least one selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol-novolak type epoxy resin, cresol-novolak type epoxy resin, rubber modified epoxy resin and urethane modified epoxy resin. desirable. Commercially available specific examples of such resins include YD-011, YD-134 and YD128 of Kukdo Chemical Co., Ltd. as bisphenol A epoxy resins, and YDPN638 of Kukdo Chemical Co., Ltd. as phenol-novolak type epoxy resins, and cresol-novolak Examples of epoxy resins include YDCN701, YDCN500-80P and YDCN500-90P from Kukdo Chemical Co., Ltd. and UME-305 and UME-330 from Kukdo Chemical Co., Ltd. as urethane modified epoxy resins. , KR207.

And the content of the epoxy resin is 5 to 50 parts by weight, preferably 10 to 35 parts by weight can be used. If the content of the epoxy resin is less than 10 parts by weight of the lead bath heat resistance is not sufficient, if the content of more than 35 parts by weight the effect of improving the adhesion between the copper foil and the insulating substrate is insignificant.

The epoxy compound used in the present invention is preferably an epoxy resin having two or more epoxy groups in a molecule, and includes glycerol poly glycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, and sorbitol polyglycidyl. Ethers and the like.

The curing agent of the adhesive composition for flexible copper-clad laminate according to the present invention preferably comprises at least one of an amine curing agent, a guanidine-based curing agent, an imidazole curing agent, a phenol-based curing agent or an acid anhydride-based curing agent, in particular triethanolamine, dimethylethanol Tertiary amine curing agents having excellent heat resistance such as amines are preferred. The tertiary amine improves the dispersibility and stability of the acrylic emulsion, serves to adjust to have a viscosity of 100 ~ 1000cps suitable for the coating, and also serves to promote the crosslinking reaction in the heat treatment process. In this case, the amount of the curing agent is used in the range of 0.05 to 5 parts by weight with respect to 100 parts by weight of the acrylic copolymer resin, because when insufficient or excessive, solvent resistance, heat resistance, and the like are lowered.

Adhesive composition for flexible copper-clad laminate according to the present invention is an additive to add a flame retardant compound and an inorganic filler, it is preferable that such flame retardant compounds include at least one of fluorine compounds, chlorine compounds, bromine compounds or iodine compounds, The inorganic filler preferably includes at least one of aluminum oxide, magnesium oxide, silicon oxide, titanium oxide, antinium oxide, zinc oxide or molybdenum oxide. The flame retardant compound is particularly preferably a compound containing a halogen or phosphorus component, and the inorganic filler is preferably antimony oxide. At this time, the flame retardant and the inorganic filler are preferably used in the range of 5 to 50 parts by weight, 1 to 30 parts by weight with respect to 100 parts by weight of the acrylic resin.

Adhesive composition prepared according to the present invention as described above is generally used in the adhesive tape manufacturing process to have a viscosity of 80 ~ 1000cps, that is, the adhesive composition is applied so that the thickness after drying on the heat-resistant film is 5 ~ 30㎛ After drying for 1 to 20 minutes at 60 ~ 120 ℃ laminated 3 ~ 50Kg / using a metal roll or heat-resistant rubber roll heated to 100 ~ 150 ℃ laminated laminated rolled copper foil, electrolytic copper foil, aluminum foil, etc. Adhesion by pressing at a pressure of ㎠ and curing for 3 to 48 hours at 80 ~ 200 ℃ to obtain a flexible copper clad laminated film, and in the case of coverlay film, instead of attaching a copper plate to a release-treated film or paper and to 80 ~ 120 ℃ The coverlay film is subjected to a semi-curing process for 5 to 30 minutes, and the coverlay film is printed on a flexible copper clad laminate and then laminated thereon, and the thickness of 10 to 60 kg / cm 2 at 160 to 200 ° C. Bond with a press for 30 to 90 minutes under pressure.

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

Example 1

30 parts by weight of acrylonitrile, 60 parts by weight of butyl acrylate, 5 parts by weight of methacrylic acid, and 5 parts by weight of hydroxy ethyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. Then, KPS was dissolved in distilled water and used as a polymerization initiator, and the previously prepared monomer mixture solution was added dropwise for 1 hour while stirring the aqueous solution which was raised to a temperature of 75 ° C. Then, the aging reaction was further performed at 85 ° C for 2 hours. After the reaction was completed, the temperature was cooled to room temperature to obtain an acrylic resin having a solid content of 27.5 wt%, whereby a low molecular weight acrylic polymer having a weight average molecular weight of 570,000 acrylic resin was obtained.

40 parts by weight of acrylonitrile, 50 parts by weight of butyl acrylate, 5 parts by weight of methacrylic acid, and 5 parts by weight of hydroxy ethyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. Then, KPS was dissolved in distilled water and used as a polymerization initiator, and the monomer mixture prepared in advance was added dropwise for 4 hours while stirring the aqueous solution which was raised to 60 ° C, and then aged at 65 ° C for 5 hours. After the reaction was completed, the temperature was cooled to room temperature to obtain an acrylic resin having a solid content of 42.5% by weight, whereby an ultrahigh molecular weight acrylic polymer having a weight average molecular weight of 2,500,000 was obtained.

100 parts by weight of the acrylic copolymer resin (3% by weight of the low molecular weight acrylic copolymer and 97% by weight of the ultra high molecular weight acrylic copolymer) and 40 parts by weight of the polyfunctional epoxy resin (trade name: EX-614, NAGASE), silane coupling agent 0.5 An adhesive composition was prepared by adjusting the viscosity of the solution to 1,200 cps using 0.38 parts by weight of dimethylethanolamine, 2 parts by weight of antimony oxide particles, and 45 parts by weight of a flame retardant (trade name: HP-36, GREAT LAKES) as parts by weight and an amine curing agent. It was.

Using this adhesive, it was applied on a polyimide film (trade name: KAPTON, DUPONT) having a thickness of 25 μm and dried (120 ° C. for 5 minutes), followed by laminating an electrolytic copper foil having a thickness of 35 μm, using a rubber roll at 140 ° C., After lamination under the conditions of a temperature and pressure of 15Kg / ㎠ and postcure at 130 ℃ for 15 hours to completely cure the adhesive layer. After printing the circuit on the flexible copper clad laminated film, attach the coverlay film (trade name: KCC, TORY Co., Ltd.) from which the release film was removed, and then attach it to the printed circuit by bonding it under pressure and temperature of 160 ℃ and 30Kg / ㎠ using a press. A flexible copper clad laminate film for a flexible printed circuit board was manufactured.

Example 2

100 parts by weight of the acrylic copolymer resin of Example 1 (5% by weight of the low molecular weight acrylic copolymer and 95% by weight of the high molecular weight acrylic copolymer) and 40 parts by weight of the polyfunctional water-soluble epoxy resin (trade name: EX-614, NAGASE Corporation) Using the amine hardener, 0.38 parts by weight of dimethylethanolamine, 2 parts by weight of antimony oxide particles, and 45 parts by weight of a flame retardant (trade name: HP-36, GREAT LAKES Co., Ltd.), an adhesive composition having a viscosity of 1,200 cps was prepared. A flexible copper foil laminated film was prepared in the same manner as in Example 1.

Example 3

100 parts by weight of the acrylic copolymer resin of Example 1 (10% by weight of the low molecular weight acrylic copolymer and 90% by weight of the high molecular weight acrylic copolymer) and 40 parts by weight of the polyfunctional epoxy resin (trade name: EX-614, NAGASE Corporation), Using an amine hardener, 0.38 parts by weight of dimethylethanolamine, 2 parts by weight of antimony oxide particles, and 45 parts by weight of a flame retardant (trade name: HP-36, GREAT LAKES Co., Ltd.) prepared an adhesive composition having a viscosity of 1,200 cps. A flexible copper foil laminated film was prepared in the same manner as in Example 1.

Example 4

30 parts by weight of acrylonitrile, 60 parts by weight of butyl acrylate, 5 parts by weight of methacrylic acid, and 5 parts by weight of hydroxy ethyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. Then, KPS was dissolved in distilled water and used as a polymerization initiator, and the previously prepared monomer mixture solution was added dropwise for 1 hour while stirring the aqueous solution which was raised to a temperature of 75 ° C. Then, the aging reaction was further performed at 85 ° C for 2 hours. After the reaction was completed, the temperature was cooled to room temperature to obtain an acrylic copolymer resin having a solid content of 27.5% by weight. At this time, a low molecular weight acrylic polymer having a weight average molecular weight of 500,000 acrylic copolymer resin was obtained.

50 parts by weight of acrylonitrile, 40 parts by weight of butyl acrylate, 3 parts by weight of methacrylic acid, and 5 parts by weight of hydroxy ethyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. KPS was dissolved in distilled water and used as a polymerization initiator, and the monomer mixture prepared in advance was added dropwise for 4 hours while stirring the aqueous solution heated to 60 ° C, and then aged at 65 ° C for 5 hours. After the reaction was completed, the temperature was cooled to room temperature to obtain an acrylic resin having a solid content of 42.5% by weight, whereby an ultrahigh molecular weight acrylic copolymer having a weight average molecular weight of 2,450,000 was obtained.

100 parts by weight of the acrylic copolymer resin (3% by weight of the low molecular weight acrylic copolymer and 97% by weight of the ultra high molecular weight acrylic copolymer) and 40 parts by weight of the polyfunctional epoxy resin (trade name: EX-614, NAGASE Corporation), dimethyl as an amine curing agent 0.38 parts by weight of ethanolamine, 2 parts by weight of antimony oxide particles, and 45 parts by weight of a flame retardant (trade name: HP-36, GREAT LAKES Co., Ltd.) prepared an adhesive composition in which the viscosity of the solution was adjusted to 1,200 cps. A flexible copper foil laminated film was prepared by the method.

 Comparative Example 1

30 parts by weight of acrylonitrile, 60 parts by weight of butyl acrylate, 5 parts by weight of glycidyl methacrylate, and 5 parts by weight of hydroxy ethyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. KPS was dissolved in distilled water and used as a polymerization initiator, and the monomer mixture prepared in advance was added dropwise for 3.5 hours while stirring the aqueous solution of which the temperature was raised to 70 ° C. Then, the aging reaction was further performed at 70 ° C for 4.5 hours. After the reaction was completed, the temperature was cooled to room temperature to obtain an acrylic resin having a solid content of 40% by weight, whereby a high molecular weight acrylic polymer having a weight average molecular weight of 1,200,000 was obtained.

100 parts by weight of the acrylic copolymer resin and 40 parts by weight of a polyfunctional epoxy resin (trade name: EX-614, NAGASE Corporation), 0.38 parts by weight of dimethylethanolamine as an amine curing agent, 2 parts by weight of antimony oxide particles, and a flame retardant (brand name: HP- 36, GREAT LAKES) 45 parts by weight of the adhesive composition was prepared by adjusting the viscosity of the solution to 1,000 cps.

Using this adhesive, it was applied on a polyimide film (trade name: KAPTON, DUPONT) having a thickness of 25 μm and dried (120 ° C., 5 minutes), followed by laminating an electrolytic copper foil having a thickness of 35 μm, using a rubber roll at 140 ° C., After lamination under the conditions of a temperature and pressure of 15Kg / ㎠ and postcure at 130 ℃ for 15 hours to completely cure the adhesive layer. After printing the circuit on the flexible copper clad laminate, coverlay film (trade name: KCC, TORY Co., Ltd.) from which the release film was removed was pasted onto the printed circuit, and then bonded at 160 ℃ and 30Kg / ㎠ using a press. A flexible copper foil laminated film for a printed circuit board was prepared.

Comparative Example 2

40 parts by weight of acrylonitrile, 50 parts by weight of butyl acrylate, 5 parts by weight of glycidyl methacrylate, and 5 parts by weight of hydroxy ethyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. KPS was dissolved in distilled water and used as a polymerization initiator, and the monomer mixture prepared in advance was added dropwise for 3.5 hours while stirring the aqueous solution heated to 70 ° C, and then aged at 4.5 ° C for 4.5 hours. After the reaction was completed, the temperature was cooled to room temperature to obtain an acrylic copolymer resin having a solid content of 40% by weight. At this time, a high molecular weight acrylic copolymer having a weight average molecular weight of 1,200,000 was obtained.

100 parts by weight of the acrylic copolymer resin and 40 parts by weight of a polyfunctional epoxy resin (trade name: EX-614, NAGASE Corporation), 0.38 parts by weight of dimethylethanolamine as an amine curing agent, 2 parts by weight of antimony oxide particles, and a flame retardant (brand name: HP- 36, GREAT LAKES) 45 parts by weight of the adhesive composition was prepared by adjusting the viscosity of the solution to 1,000cps, and then a flexible copper foil laminated film was prepared in the same manner as in Comparative Example 1.

Experimental Example

Adhesive strength

Adhesion strength between copper foil and heat resistant film is measured according to ICP-FC-240B. The measurement conditions were temperature 20 ℃, to measure 180 ^peeling strength after allowed to stand at a relative humidity of 65% for 48 hours.

Solder Heat Resistance

Plot the wiring surface on the lead melt at 260 ° C for 60 seconds and observe the appearance.

Flame retardant

The adhesive layer is applied on a polyimide film at 30 占 퐉, and then dried at 100 ° C. for 5 minutes, and then tested for flame retardancy according to the UL94 standard with a sample having a width of 1 cm and a length of 12.7 cm.

Chemical resistance

According to JISC 6181, the test piece is immersed in acetone and methylene chloride at room temperature for 15 minutes, and then taken out and observed.

Long-term heat resistance

The specimen is stored at 150 ° C. for 120 hours and then measured for adhesion.

Insulation Resistance

According to JISC 6181, insulation resistance is measured after leaving for 96 hours at the temperature of 40 degreeC and 90% of a relative humidity.

The results of measuring the Examples and Comparative Examples through the Experimental Example are shown in Table 1 below.

TABLE 1

Evaluation item Adhesion (kg / cm) Long term heat resistance (kg / cm) Soldering heat resistance Chemical resistance flexibility Insulation Resistance Example 1 2.5 2.4 ○ ○ △ 10 ¹³ Example 2 2.4 2.2 ○ ○ ○ 10 ¹³ Example 3 2.4 2.0 △ △ ○ 10 ¹³ Example 4 2.5 2.3 ○ ○ ○ 10 ¹³ Comparative Example 1 1.6 1.4 △ △ △ 10 ¹³ Comparative Example 2 2.0 1.6 △ △ △ 10 ¹³

Poor: X, Good: △, Excellent: ○

As can be seen in Table 1, it can be seen that the adhesive composition for a flexible copper-clad laminated film according to an embodiment of the present invention is superior in adhesive strength, long-term heat resistance, soldering heat resistance, chemical resistance and flexibility compared to the adhesive composition according to the comparative example. have.

As described above, according to the adhesive composition for flexible copper-clad laminate according to the present invention, the acrylic copolymer resin is mixed with a low molecular weight acrylic copolymer and an ultra high molecular weight acrylic copolymer, thereby having flexibility due to the low content acrylic copolymer, Due to the molecular weight acrylic copolymer has the effect of having excellent heat resistance and adhesion. Therefore, the use of such an adhesive composition can produce a flexible copper clad laminated film for a flexible printed circuit board having excellent properties such as excellent adhesion, long-term heat resistance, soldering heat resistance, chemical resistance, flexibility, insulation, and the like. have.

Claims (7)

An adhesive composition for a flexible copper foil laminated film in which an insulating film, an adhesive, and copper foil are laminated, The adhesive composition (a) 100 parts by weight of the acrylic copolymer resin consisting of 1 to 20% by weight of the acrylic copolymer having a weight average molecular weight of 500 to 500,000 and 80 to 99% by weight of the acrylic copolymer having a weight average molecular weight of 1,500,000 to 3,500,000, (b) 5 to 50 parts by weight of an epoxy resin having two or more epoxy groups, (c) 0.05 to 5 parts by weight of a curing agent, (d) 5 to 50 parts by weight of a flame retardant compound, and (e) 1 to 30 parts by weight of an inorganic filler, The flame retardant compound is at least one of a fluorine-based compound, chlorine-based compound, bromine-based compound or iodine-based compound, adhesive composition for flexible copper foil laminated film. The method of claim 1, The acrylic copolymer resin is acrylonitrile, alkyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, n-octyl acrylate, acrylic acid, methacrylic acid, itaconic acid, 4-hydroxybutyl acryl Ductile, characterized in that it is prepared using at least one of 2-hydroxyethyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate or 2-hydroxypropylene glycol (meth) acrylate. Adhesive composition for copper foil laminated films. The method of claim 2, The acrylic copolymer resin is 10 to 50 parts by weight of acrylonitrile, 40 to 80 parts by weight of alkyl acrylate having an alkyl group having 2 to 12 carbon atoms, 1 to 10 parts by weight of acrylic acid or methacrylic acid and hydroxyethyl acrylate or hydroxy Roxy ethyl methacrylate 1 to 5 parts by weight, characterized in that the flexible copper foil laminated film adhesive composition. The method of claim 1, The epoxy resin is at least one of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol noblock type epoxy resin, a cresol noblock type epoxy resin, or a rubber-modified epoxy resin, adhesive composition for a flexible copper clad laminated film. The method of claim 1, The curing agent is at least one of an amine curing agent, a guanidine-based curing agent, an imidazole curing agent, a phenol curing agent or an acid anhydride curing agent, adhesive composition for a flexible copper-clad laminated film. delete The method of claim 1, The inorganic filler is at least one of aluminum oxide, magnesium oxide, silicon oxide, titanium oxide, antinium oxide, zinc oxide or molybdenum oxide, adhesive composition for a flexible copper clad laminated film.